Appendix H: Calculations

Current loading of the XT+ Extinguishant Control Panel is limited to the capacity of the power supplies. Installers must determine the loading placed on these power supplies by adding the sum of device loads to the no load alarm current of the XT+ Extinguishant Control Panel. The result obtained from this calculation must be below the operating current of the power supply.

The 5.25 Amp Power Supply operates the fire control panel and external loads with 5.25 Amps and reserves 1.25 Amps for charging the standby batteries.

The 10.25 Amp Power Supply operates the fire control panel and external loads with 10.25 Amps and reserves 2.25 Amps for charging the standby batteries.

Current limits are provided in Specifications for outputs of the XT+ Extinguishant Control Panel. Total device currents must be below limits provided for all outputs of the fire control panel.

The calculation of total current loading must include the sum of device loads on the circuit outputs of the XT+ Extinguishant Control Panel. Circuits to be included in this calculation for total current loading are:

  • SLC Loops
  • NAC Outputs
  • 24V OUT
  • AUX 24V
  • Peripheral Interface Modules
  • Network Module
  • Panel Standby and Alarm Currents

The current limits provided in Specifications are maximums for individual outputs of the fire control panel. These output-levels are not intended to be summed together to determine the total current available from the XT+ Extinguishant Control Panel. Refer to these levels only when determining the limit of device-loading on each output circuit.

SLC Loop Cabling

The XT+ Extinguishant Control Panel requires that SLC Loops include wire gauge and lengths specified in tables of this section.

The maximum allowable voltage drop of 5.5 volts is necessary on the SLC loop to maintain the minimum device operating voltage of 17 volts. The worst case voltage drop occurs when the load is located at the farthest point from the terminals of the fire control panel. The worst case range of voltage at the source (Vsource) is 23 to 30.5 volts.

Example Voltage Drop Condition

The following example demonstrates the impact of cable size and length on output circuits. A twin-wire of 16 AWG cabling is connected to SLC loop 1. The length of the 16 AWG cable is 1000 ft (305 m) and the device-load on the loop is 400 mA. The device-load of 400 mA is determined from manufacturer data sheets. The following figure illustrates the example SLC voltage drop condition of 16 AWG cable:

A voltage-drop of 1.6064V DC is determined from the table of 16 AWG cable for a single wire length of 1000 ft (305 m) and a load of 400 mA. The resistance of one wire of the 16 AWG cable is 4.016 Ω at 1000 ft.

Voltage-drop of the twin cable

(Vcable 1 + Vcable 2) = (1.6064V DC + 1.6064V DC) = 3.2128V DC

Voltage at the load

Vload = Vsource - (Vcable 1 + Vcable 2) = 24V DC - (1.6064V DC + 1.6064V DC) = 20.7872V DC

A voltage of 20.7872 VDC is available to operate the device at this circuit location.

Shading of the SLC tables identify cable length and load combinations that are not permitted for SLC loop devices. Dark shading represents cable lengths that are not permitted when SLC circuits contain five or more isolators. Light shading represents cable lengths that are not permitted without the connection of isolators in the SLC circuit.

Twin cables are connected to SLC loop terminals of the XT+ Extinguishant Control Panel. Data provided in SLC tables of this section represent resistance and voltage from a single cable-conductor. Resistance and voltage levels obtained from these tables must include the secondary conductor of the twin cable during the evaluation process. SLC tables are provided for the following recommended wire gauges:

14 AWG

2.525 Ohms / 1000 ft

16 AWG

4.016 Ohms / 1000 ft

18 AWG

6.385 Ohms / 1000 ft

14 AWG Cable

Length
in feet

Resistance

Voltage Drop

@ 0.1 A

@ 0.2 A

@ 0.3 A

@ 0.4 A

@ 0.5 A

100

0.2525

0.02525

0.0505

0.07575

0.101

0.12625

200

0.505

0.0505

0.101

0.1515

0.202

0.2525

300

0.7575

0.07575

0.1515

0.22725

0.303

0.37875

400

1.01

0.101

0.202

0.303

0.404

0.505

500

1.2625

0.12625

0.2525

0.37875

0.505 0

0.63125

600

1.515

0.1515

0.303

0.4545

0.606

0.7575

700

1.7675

0.17675

0.3535

0.53025

0.707

0.88375

800

2.02

0.202

0.404

0.606

0.808

1.01

900

2.2725

0.22725

0.4545

0.68175

0.909

1.13625

1000

2.525

0.2525

0.505

0.7575

1.01

1.2625

1100

2.7775

0.27775

0.5555

0.83325

1.111

1.38875

1200

3.03

0.303

0.606

0.909

1.212

1.515

1300

3.2825

0.32825

0.6565

0.98475

1.313

1.64125

1400

3.535

0.3535

0.707

1.0605

1.414

1.7675

1500

3.7875

0.37875

0.7575

1.13625

1.515

1.89375

1600

4.04

0.404

0.808

1.212

1.616

2.02

1700

4.2925

0.42925

0.8585

1.28775

1.717

2.14625

1800

4.545

0.4545

0.909

1.3635

1.818

2.2725

1900

4.7975

0.47975

0.9595

1.43925

1.919

2.39875

2000

5.05

0.505

1.01

1.515

2.02

2.525

2100

5.3025

0.53025

1.0605

1.59075

2.121

2.65125

2200

5.555

0.5555

1.111

1.6665

2.222

2.7775

2300

5.8075

0.58075

1.1615

1.74225

2.323

2.90375

2400

6.06

0.606

1.212

1.818

2.424

3.03

2500

6.3125

0.63125

1.2625

1.89375

2.525

3.15625

2600

6.565

0.6565

1.313

1.9695

2.626

3.2825

2700

6.8175

0.68175

1.3635

2.04525

2.727

3.40875

2800

7.07

0.707

1.414

2.121

2.828

3.535

2900

7.3225

0.73225

1.4645

2.19675

2.929

3.66125

3000

7.575

0.7575

1.515

2.2725

3.03

3.7875

3100

7.8275

0.78275

1.5655

2.34825

3.131

3.91375

3200

8.08

0.808

1.616

2.424

3.232

4.04

3300

8.3325

0.83325

1.6665

2.49975

3.333

4.16625

3400

8.585

0.8585

1.717

2.5755

3.434

4.2925

3500

8.8375

0.88375

1.7675

2.65125

3.535

4.41875

3600

9.09

0.909

1.818

2.727

3.636

4.545

3700

9.3425

0.93425

1.8685

2.80275

3.737

4.67125

3800

9.595

0.9595

1.919

2.8785

3.838

4.7975

3900

9.8475

0.98475

1.9695

2.95425

3.939

4.92375

4000

10.1

1.01

2.02

3.03

4.04

5.05

4100

10.3525

1.03525

2.0705

3.10575

4.141

5.17625

4200

10.605

1.0605

2.121

3.1815

4.242

5.3025

4300

10.8575

1.08575

2.1715

3.25725

4.343

5.42875

4400

11.11

1.111

2.222

3.333

4.444

5.555

4500

11.3625

1.13625

2.2725

3.40875

4.545

5.68125

4600

11.615

1.1615

2.323

3.4845

4.646

5.8075

4700

11.8675

1.18675

2.3735

3.56025

4.747

5.93375

4800

12.12

1.212

2.424

3.636

4.848

6.06

4900

12.3725

1.23725

2.4745

3.71175

4.949

6.18625

5000

12.625

1.2625

2.525

3.7875

5.05

6.3125

5100

12.8775

1.28775

2.5755

3.86325

5.151

6.43875

5200

13.13

1.313

2.626

3.939

42

6.565

5300

13.3825

1.33825

2.6765

4.01475

5.353

6.69125

5400

13.635

1.3635

2.727

4.0905

5.454

6.8175

5500

13.8875

1.38875

2.7775

4.16625

5.555

6.94375

5600

14.14

1.414

2.828

4.242

5.656

7.07

5700

14.3925

1.43925

2.8785

4.31775

5.757

7.19625

5800

14.645

1.4645

2.929

4.3935

5.858

7.3225

5900

14.8975

1.48975

2.9795

4.46925

5.959

7.44875

6000

15.15

1.515

3.03

4.545

6.06

7.575

6100

15.4025

1.54025

3.0805

4.62075

6.161

7.70125

6200

15.655

1.5655

3.131

4.6965

6.262

7.8275

6300

15.9075

1.59075

3.1815

4.77225

6.363

7.95375

6400

16.16

1.616

3.232

4.848

6.464

8.08

6500

16.4125

1.64125

3.2825

4.92375

6.565

8.20625

6600

16.665

1.6665

3.333

4.9995

6.666

8.3325

16 AWG Cable

Length
in feet
Resistance
Voltage Drop

@ 0.1 A

@ 0.2 A

@ 0.3 A

@ 0.4 A

@ 0.5 A

100

0.4016

0.04016

0.08032

0.12048

0.16064

0.2008

200

0.8032

0.08032

0.16064

0.24096

0.32128

0.4016

300

1.2048

0.12048

0.24096

0.36144

0.48192

0.6024

400

1.6064

0.16064

0.32128

0.48192

0.64256

0.8032

500

2.008

0.2008

0.4016

0.6024

0.8032

1.004

600

2.4096

0.24096

0.48192

0.72288

0.96384

1.2048

700

2.8112

0.28112

0.56224

0.84336

1.12448

1.4056

800

3.2128

0.32128

0.64256

0.96384

1.28512

1.6064

900

3.6144

0.36144

0.72288

1.08432

1.44576

1.8072

1000

4.016

0.4016

0.8032

1.2048

1.6064

2.008

1100

4.4176

0.44176

0.88352

1.32528

1.76704

2.2088

1200

4.8192

0.48192

0.96384

1.44576

1.92768

2.4096

1300

5.2208

0.52208

1.04416

1.56624

2.08832

2.6104

1400

5.6224

0.56224

1.12448

1.68672

2.24896

2.8112

1500

6.024

0.6024

1.2048

1.8072

2.4096

3.012

1600

6.4256

0.64256

1.28512

1.92768

2.57024

3.2128

1700

6.8272

0.68272

1.36544

2.04816

2.73088

3.4136

1800

7.2288

0.72288

1.44576

2.16864

2.89152

3.6144

1900

7.6304

0.76304

1.52608

2.28912

3.05216

3.8152

2000

8.032

0.8032

1.6064

2.4096

3.2128

4.016

2100

8.4336

0.84336

1.68672

2.53008

3.37344

4.2168

2200

8.8352

0.88352

1.76704

2.65056

3.53408

4.4176

2300

9.2368

0.92368

1.84736

2.77104

3.69472

4.6184

2400

9.6384

0.96384

1.92768

2.89152

3.85536

4.8192

2500

10.04

1.004

2.008

3.012

4.016

5.02

2600

10.4416

1.04416

2.08832

3.13248

4.17664

5.2208

2700

10.8432

1.08432

2.16864

3.25296

4.33728

5.4216

2800

11.2448

1.12448

2.24896

3.37344

4.49792

5.6224

2900

11.6464

1.16464

2.32928

3.49392

4.65856

5.8232

3000

12.048

1.2048

2.4096

3.6144

4.8192

6.024

3100

12.4496

1.24496

2.48992

3.73488

4.97984

6.2248

3200

12.8512

1.28512

2.57024

3.85536

5.14048

6.4256

3300

13.2528

1.32528

2.65056

3.97584

5.30112

6.6264

3400

13.6544

1.36544

2.73088

4.09632

5.46176

6.8272

3500

14.056

1.4056

2.8112

4.2168

5.6224

7.028

3600

14.4576

1.44576

2.89152

4.33728

5.78304

7.2288

3700

14.8592

1.48592

2.97184

4.45776

5.94368

7.4296

3800

15.2608

1.52608

3.05216

4.57824

6.10432

7.6304

3900

15.6624

1.56624

3.13248

4.69872

6.26496

7.8312

4000

16.064

1.6064

3.2128

4.8192

6.4256

8.032

4100

16.4656

1.64656

3.29312

4.93968

6.58624

8.2328

4200

16.8672

1.68672

3.37344

5.06016

6.74688

8.4336

4300

17.2688

1.72688

3.45376

5.18064

6.90752

8.6344

4400

17.6704

1.76704

3.53408

5.30112

7.06816

8.8352

4500

18.072

1.8072

3.6144

5.4216

7.2288

9.036

4600

18.4736

1.84736

3.69472

5.54208

7.38944

9.2368

4700

18.8752

1.88752

3.77504

5.66256

7.55008

9.4376

4800

19.2768

1.92768

3.85536

5.78304

7.71072

9.6384

4900

19.6784

1.96784

3.93568

5.90352

7.87136

9.8392

5000

20.08

2.008

4.016

6.024

8.032

10.04

5100

20.4816

2.04816

4.09632

6.14448

8.19264

10.2408

5200

20.8832

2.08832

4.17664

6.26496

8.35328

10.4416

5300

21.2848

2.12848

4.25696

6.38544

8.51392

10.6424

5400

21.6864

2.16864

4.33728

6.50592

8.67456

10.8432

5500

22.088

2.2088

4.4176

6.6264

8.8352

11.044

5600

22.4896

2.24896

4.49792

6.74688

8.99584

11.2448

5700

22.8912

2.28912

4.57824

6.86736

9.15648

11.4456

5800

23.2928

2.32928

4.65856

6.98784

9.31712

11.6464

5900

23.6944

2.36944

4.73888

7.10832

9.47776

11.8472

6000

24.096

2.4096

4.8192

7.2288

9.6384

12.048

6100

24.4976

2.44976

4.89952

7.34928

9.79904

12.2488

6200

24.8992

2.48992

4.97984

7.46976

9.95968

12.4496

6300

25.3008

2.53008

5.06016

7.59024

10.12032

12.6504

6400

25.7024

2.57024

5.14048

7.71072

10.28096

12.8512

6500

26.104

2.6104

5.2208

7.8312

10.4416

13.052

6600

26.5056

2.65056

5.30112

7.95168

10.60224

13.2528

18 AWG Cable

Length
in feet
Resistance
Voltage Drop

@ 0.1 A

@ 0.2 A

@ 0.3 A

@ 0.4 A

@ 0.5 A

100

0.6385

0.06385

0.1277

0.19155

0.2554

0.31925

200

1.277

0.1277

0.2554

0.3831

0.5108

0.6385

300

1.9155

0.19155

0.3831

0.57465

0.7662

0.95775

400

2.554

0.2554

0.5108

0.7662

1.0216

1.277

500

3.1925

0.31925

0.6385

0.95775

1.277

1.59625

600

3.831

0.3831

0.7662

1.1493

1.5324

1.9155

700

4.4695

0.44695

0.8939

1.34085

1.7878

2.23475

800

5.108

0.5108

1.0216

1.5324

2.0432

2.554

900

5.7465

0.57465

1.1493

1.72395

2.2986

2.87325

1000

6.385

0.6385

1.277

1.9155

2.554

3.1925

1100

7.0235

0.70235

1.4047

2.10705

2.8094

3.51175

1200

7.662

0.7662

1.5324

2.2986

3.0648

3.831

1300

8.3005

0.83005

1.6601

2.49015

3.3202

4.15025

1400

8.939

0.8939

1.7878

2.6817

3.5756

4.4695

1500

9.5775

0.95775

1.9155

2.87325

3.831

4.78875

1600

10.216

1.0216

2.0432

3.0648

4.0864

5.108

1700

10.8545

1.08545

2.1709

3.25635

4.3418

5.42725

1800

11.493

1.1493

2.2986

3.4479

4.5972

5.7465

1900

12.1315

1.21315

2.4263

3.63945

4.8526

6.06575

2000

12.77

1.277

2.554

3.831

5.108

6.385

2100

13.4085

1.34085

2.6817

4.02255

5.3634

6.70425

2200

14.047

1.4047

2.8094

4.2141

5.6188

7.0235

2300

14.6855

1.46855

2.9371

4.40565

5.8742

7.34275

2400

15.324

1.5324

3.0648

4.5972

6.1296

7.662

2500

15.9625

1.59625

3.1925

4.78875

6.385

7.98125

2600

16.601

1.6601

3.3202

4.9803

6.6404

8.3005

2700

17.2395

1.72395

3.4479

5.17185

6.8958

8.61975

2800

17.878

1.7878

3.5756

5.3634

7.1512

8.939

2900

18.5165

1.85165

3.7033

5.55495

7.4066

9.25825

3000

19.155

1.9155

3.831

5.7465

7.662

9.5775

3100

19.7935

1.97935

3.9587

5.93805

7.9174

9.89675

3200

20.432

2.0432

4.0864

6.1296

8.1728

10.216

3300

21.0705

2.10705

4.2141

6.32115

8.4282

10.53525

3400

21.709

2.1709

4.3418

6.5127

8.6836

10.8545

3500

22.3475

2.23475

4.4695

6.70425

8.939

11.17375

3600

22.986

2.2986

4.5972

6.8958

9.1944

11.493

3700

23.6245

2.36245

4.7249

7.08735

9.4498

11.81225

3800

24.263

2.4263

4.8526

7.2789

9.7052

12.1315

3900

24.9015

2.49015

4.9803

7.47045

9.9606

12.45075

4000

25.54

2.554

5.108

7.662

10.216

12.77

4100

26.1785

2.61785

5.2357

7.85355

10.4714

13.08925

4200

26.817

2.6817

5.3634

8.0451

10.7268

13.4085

4300

27.4555

2.74555

5.4911

8.23665

10.9822

13.72775

4400

28.094

2.8094

5.6188

8.4282

11.2376

14.047

4500

28.7325

2.87325

5.7465

8.61975

11.493

14.36625

4600

29.371

2.9371

5.8742

8.8113

11.7484

14.6855

4700

30.0095

3.00095

6.0019

9.00285

12.0038

15.00475

4800

30.648

3.0648

6.1296

9.1944

12.2592

15.324

4900

31.2865

3.12865

6.2573

9.38595

12.5146

15.64325

5000

31.925

3.1925

6.385

9.5775

12.77

15.9625

5100

32.5635

3.25635

6.5127

9.76905

13.0254

16.28175

5200

33.202

3.3202

6.6404

9.9606

13.2808

16.601

5300

33.8405

3.38405

6.7681

10.15215

13.5362

16.92025

5400

34.479

3.4479

6.8958

10.3437

13.7916

17.2395

5500

35.1175

3.51175

7.0235

10.53525

14.047

17.55875

5600

35.756

3.5756

7.1512

10.7268

14.3024

17.878

5700

36.3945

3.63945

7.2789

10.91835

14.5578

18.19725

5800

37.033

3.7033

7.4066

11.1099

14.8132

18.5165

5900

37.6715

3.76715

7.5343

11.30145

15.0686

18.83575

6000

38.31

3.831

7.662

11.493

15.324

19.155

6100

38.9485

3.89485

7.7897

11.68455

15.5794

19.47425

6200

39.587

3.9587

7.9174

11.8761

15.8348

19.7935

6300

40.2255

4.02255

8.0451

12.06765

16.0902

20.11275

6400

40.864

4.0864

8.1728

12.2592

16.3456

20.432

6500

41.5025

4.15025

8.3005

12.45075

16.601

20.75125

6600

42.141

4.2141

8.4282

12.6423

16.8564

21.0705

NAC Cabling

The XT+ Extinguishant Control Panel requires that NAC circuits include wire gauge and lengths specified in tables of this section. Shading of the tables identify cable length and load combinations that are not permitted for NAC devices.

Twin cables are connected to NAC terminals of the XT+ Extinguishant Control Panel. Data provided in the tables of this section represent resistance and voltage from a single cable-conductor. Resistance and voltage levels obtained from these tables must include the secondary conductor of the twin cable during the evaluation process.

Cable length values in the tables represent worst case conditions with the total load at the farthest point from terminals of the fire control panel. Voltage drops are represented with a depleted battery of 20.4V. Minimum output voltage is 20V. maximum allowable voltage drop is 4V to ensure a minimum of 16V at the device.

Tables are provided for the following recommended wire gauges:

12 AWG

1.588 Ohms / 1000 ft

14 AWG

2.525 Ohms / 1000 ft

16 AWG

4.016 Ohms / 1000 ft

12 AWG Cable

Length
(in feet)

Resistance
Voltage Drop
@ 0.25 A @ 0.5 A @ 0.75 A @ 1.0 A @ 1.25 A @ 1.50 A @ 1.75 A @ 2.00 A @ 2.25 A @ 2.50 A

25

0.0397

0.00992

0.01985

0.02977

0.0397

0.049625

0.05955

0.069475

0.0794

0.089325

0.09925

50

0.07964

0.01991

0.03982

0.05973

0.07964

0.09955

0.11946

0.13937

0.15928

0.17919

0.1991

100

0.15944

0.03986

0.07972

0.11958

0.15944

0.1993

0.23916

0.27902

0.31888

0.35874

0.3986

150

0.23924

0.05981

0.11962

0.17943

0.23924

0.29905

0.35886

0.41867

0.47848

0.53829

0.5981

200

0.31904

0.07976

0.15952

0.23928

0.31904

0.3988

0.47856

0.55832

0.63808

0.71784

0.7976

250

0.39884

0.09971

0.19942

0.29913

0.39884

0.49855

0.59826

0.69797

0.79768

0.89739

0.9971

300

0.47864

0.11966

0.23932

0.35898

0.47864

0.5983

0.71796

0.83762

0.95728

1.07694

1.1966

350

0.55844

0.13961

0.27922

0.41883

0.55844

0.69805

0.83766

0.97727

1.11688

1.25649

1.3961

400

0.63824

0.15956

0.31912

0.47868

0.63824

0.7978

0.95736

1.11692

1.27648

1.43604

1.5956

450

0.71804

0.17951

0.35902

0.53853

0.71804

0.89755

1.07706

1.25657

1.43608

1.61559

1.7951

500

0.79784

0.19946

0.39892

0.59838

0.79784

0.9973

1.19676

1.39622

1.59568

1.79514

1.9946

550

0.87764

0.21941

0.43882

0.65823

0.87764

1.09705

1.31646

1.53587

1.75528

1.97469

2.1941

600

0.95744

0.23936

0.47872

0.71808

0.95744

1.1968

1.43616

1.67552

1.91488

2.15424

2.3936

650

1.03724

0.25931

0.51862

0.77793

1.03724

1.29655

1.55586

1.81517

2.07448

2.33379

2.5931

700

1.11704

0.27926

0.55852

0.83778

1.11704

1.3963

1.67556

1.95482

2.23408

2.51334

2.7926

750

1.19684

0.29921

0.59842

0.89763

1.19684

1.49605

1.79526

2.09447

2.39368

2.69289

2.9921

800

1.27664

0.31916

0.63832

0.95748

1.27664

1.5958

1.91496

2.23412

2.55328

2.87244

3.1916

850

1.35644

0.33911

0.67822

1.01733

1.35644

1.69555

2.03466

2.37377

2.71288

3.05199

3.3911

900

1.43624

0.35906

0.71812

1.07718

1.43624

1.7953

2.15436

2.51342

2.87248

3.23154

3.5906

950

1.51604

0.37901

0.75802

1.13703

1.51604

1.89505

2.27406

2.65307

3.03208

3.41109

3.7901

1000

1.59584

0.39896

0.79792

1.19688

1.59584

1.9948

2.39376

2.79272

3.19168

3.59064

3.9896

1050

1.67564

0.41891

0.83782

1.25673

1.67564

2.09455

2.51346

2.93237

3.35128

3.77019

4.1891

1100

1.75544

0.43886

0.87772

1.31658

1.75544

2.1943

2.63316

3.07202

3.51088

3.94974

4.3886

1150

1.83524

0.45881

0.91762

1.37643

1.83524

2.29405

2.75286

3.21167

3.67048

4.12929

4.5881

1200

1.91504

0.47876

0.95752

1.43628

1.91504

2.3938

2.87256

3.35132

3.83008

4.30884

4.7876

1250

1.99484

0.49871

0.99742

1.49613

1.99484

2.49355

2.99226

3.49097

3.98968

4.48839

4.9871

1300

2.07464

0.51866

1.03732

1.55598

2.07464

2.5933

3.11196

3.63062

4.14928

4.66794

5.1866

1350

2.15444

0.53861

1.07722

1.61583

2.15444

2.69305

3.23166

3.77027

4.30888

4.84749

5.3861

1400

2.23424

0.55856

1.11712

1.67568

2.23424

2.7928

3.35136

3.90992

4.46848

5.02704

5.5856

1450

2.31404

0.57851

1.15702

1.73553

2.31404

2.89255

3.47106

4.04957

4.62808

5.20659

5.7851

1500

2.39384

0.59846

1.19692

1.79538

2.39384

2.9923

3.59076

4.18922

4.78768

5.38614

5.9846

1550

2.47364

0.61841

1.23682

1.85523

2.47364

3.09205

3.71046

4.32887

4.94728

5.56569

6.1841

1600

2.55344

0.63836

1.27672

1.91508

2.55344

3.1918

3.83016

4.46852

5.10688

5.74524

6.3836

1650

2.63324

0.65831

1.31662

1.97493

2.63324

3.29155

3.94986

4.60817

5.26648

5.92479

6.5831

14 AWG Cable

Length
(in feet)

Resistance
Voltage Drop
@ 0.25 A @ 0.5 A @ 0.75 A @ 1.0 A @ 1.25 A @ 1.50 A @ 1.75 A @ 2.00 A @ 2.25 A @ 2.50 A

25

0.063125

0.01578125

0.0315625

0.04734375

0.063125

0.07890625

0.0946875

0.11046875

0.12625

0.14203125

0.1578125

50

0.12625

0.0315625

0.063125

0.0946875

0.12625

0.1578125

0.189375

0.2209375

0.2525

0.2840625

0.315665

100

0.2525

0.063125

0.12625

0.189375

0.2525

0.315625

0.37875

0.441875

0.505

0.568125

0.63134

150

0.37875

0.0946875

0.189375

0.2840625

0.37875

0.4734375

0.568125

0.6628125

0.7575

0.8521875

0.947015

200

0.505

0.12625

0.2525

0.37875

0.505

0.63125

0.7575

0.88375

1.01

1.13625

1.26269

250

0.63125

0.1578125

0.315625

0.4734375

0.63125

0.7890625

0.946875

1.1046875

1.2625

1.4203125

1.578365

300

0.7575

0.189375

0.37875

0.568125

0.7575

0.946875

1.13625

1.325625

1.515

1.704375

1.89404

350

0.88375

0.2209375

0.441875

0.6628125

0.88375

1.1046875

1.325625

1.5465625

1.7675

1.9884375

2.209715

400

1.01

0.2525

0.505

0.7575

1.01

1.2625

1.515

1.7675

2.02

2.2725

2.52539

450

1.13625

0.2840625

0.568125

0.8521875

1.13625

1.4203125

1.704375

1.9884375

2.2725

2.5565625

2.841065

500

1.2625

0.315625

0.63125

0.946875

1.2625

1.578125

1.89375

2.209375

2.525

2.840625

3.15674

550

1.38875

0.3471875

0.694375

1.0415625

1.38875

1.7359375

2.083125

2.4303125

2.7775

3.1246875

3.472415

600

1.515

0.37875

0.7575

1.13625

1.515

1.89375

2.2725

2.65125

3.03

3.40875

3.78809

650

1.64125

0.4103125

0.820625

1.2309375

1.64125

2.0515625

2.461875

2.8721875

3.2825

3.6928125

4.103765

700

1.7675

0.441875

0.88375

1.325625

1.7675

2.209375

2.65125

3.093125

3.535

3.976875

4.41944

750

1.89375

0.4734375

0.946875

1.4203125

1.89375

2.3671875

2.840625

3.3140625

3.7875

4.2609375

4.735115

800

2.02

0.505

1.01

1.515

2.02

2.525

3.03

3.535

4.04

4.545

5.05079

850

2.14625

0.5365625

1.073125

1.6096875

2.14625

2.6828125

3.219375

3.7559375

4.2925

4.8290625

5.366465

900

2.2725

0.568125

1.13625

1.704375

2.2725

2.840625

3.40875

3.976875

4.545

5.113125

5.68214

950

2.39875

0.5996875

1.199375

1.7990625

2.39875

2.9984375

3.598125

4.1978125

4.7975

5.3971875

5.997815

1000

2.525

0.63125

1.2625

1.89375

2.525

3.15625

3.7875

4.41875

5.05

5.68125

6.31349

1050

2.65125

0.6628125

1.325625

1.9884375

2.65125

3.3140625

3.976875

4.6396875

5.3025

5.9653125

6.629165

1100

2.7775

0.694375

1.38875

2.083125

2.7775

3.471875

4.16625

4.860625

5.555

6.249375

6.94484

1150

2.90375

0.7259375

1.451875

2.1778125

2.90375

3.6296875

4.355625

5.0815625

5.8075

6.5334375

7.260515

1200

3.03

0.7575

1.515

2.2725

3.03

3.7875

4.545

5.3025

6.06

6.8175

7.57619

1250

3.15625

0.7890625

1.578125

2.3671875

3.15625

3.9453125

4.734375

5.5234375

6.3125

7.1015625

7.891865

1300

3.2825

0.820625

1.64125

2.461875

3.2825

4.103125

4.92375

5.744375

6.565

7.385625

8.20754

1350

3.40875

0.8521875

1.704375

2.5565625

3.40875

4.2609375

5.113125

5.9653125

6.8175

7.6696875

8.523215

1400

3.535

0.88375

1.7675

2.65125

3.535

4.41875

5.3025

6.18625

7.07

7.95375

8.83889

1450

3.66125

0.9153125

1.830625

2.7459375

3.66125

4.5765625

5.491875

6.4071875

7.3225

8.2378125

9.154565

1500

3.7875

0.946875

1.89375

2.840625

3.7875

4.734375

5.68125

6.628125

7.575

8.521875

9.47024

1550

3.91375

0.9784375

1.956875

2.9353125

3.91375

4.8921875

5.870625

6.8490625

7.8275

8.8059375

9.785915

1600

4.04

1.01

2.02

3.03

4.04

5.05

6.06

7.07

8.08

9.09

10.10159

1650

4.16625

1.0415625

2.083125

3.1246875

4.16625

5.2078125

6.249375

7.2909375

8.3325

9.3740625

10.417265

16 AWG Cable

Length
(in feet)

Resistance
Voltage Drop
@ 0.25 A @ 0.5 A @ 0.75 A @ 1.0 A @ 1.25 A @ 1.50 A @ 1.75 A @ 2.00 A @ 2.25 A @ 2.50 A

25

0.1004

0.0251

0.0502

0.0753

0.1004

0.1255

0.1506

0.1757

0.2008

0.2259

0.251

50

0.2008

0.0502

0.1004

0.1506

0.2008

0.251

0.3012

0.3514

0.4016

0.4518

0.502

100

0.4016

0.1004

0.2008

0.3012

0.4016

0.502

0.6024

0.7028

0.8032

0.9036

1.004

150

0.6024

0.1506

0.3012

0.4518

0.6024

0.753

0.9036

1.0542

1.2048

1.3554

1.506

200

0.8032

0.2008

0.4016

0.6024

0.8032

1.004

1.2048

1.4056

1.6064

1.8072

2.008

250

1.004

0.251

0.502

0.753

1.004

1.255

1.506

1.757

2.008

2.259

2.51

300

1.2048

0.3012

0.6024

0.9036

1.2048

1.506

1.8072

2.1084

2.4096

2.7108

3.012

350

1.4056

0.3514

0.7028

1.0542

1.4056

1.757

2.1084

2.4598

2.8112

3.1626

3.514

400

1.6064

0.4016

0.8032

1.2048

1.6064

2.008

2.4096

2.8112

3.2128

3.6144

4.016

450

1.8072

0.4518

0.9036

1.3554

1.8072

2.259

2.7108

3.1626

3.6144

4.0662

4.518

500

2.008

0.502

1.004

1.506

2.008

2.51

3.012

3.514

4.016

4.518

5.02

550

2.2088

0.5522

1.1044

1.6566

2.2088

2.761

3.3132

3.8654

4.4176

4.9698

5.522

600

2.4096

0.6024

1.2048

1.8072

2.4096

3.012

3.6144

4.2168

4.8192

5.4216

6.024

650

2.6104

0.6526

1.3052

1.9578

2.6104

3.263

3.9156

4.5682

5.2208

5.8734

6.526

700

2.8112

0.7028

1.4056

2.1084

2.8112

3.514

4.2168

4.9196

5.6224

6.3252

7.028

750

3.012

0.753

1.506

2.259

3.012

3.765

4.518

5.271

6.024

6.777

7.53

800

3.2128

0.8032

1.6064

2.4096

3.2128

4.016

4.8192

5.6224

6.4256

7.2288

8.032

850

3.4136

0.8534

1.7068

2.5602

3.4136

4.267

5.1204

5.9738

6.8272

7.6806

8.534

900

3.6144

0.9036

1.8072

2.7108

3.6144

4.518

5.4216

6.3252

7.2288

8.1324

9.036

950

3.8152

0.9538

1.9076

2.8614

3.8152

4.769

5.7228

6.6766

7.6304

8.5842

9.538

1000

4.016

1.004

2.008

3.012

4.016

5.02

6.024

7.028

8.032

9.036

10.04

1050

4.2168

1.0542

2.1084

3.1626

4.2168

5.271

6.3252

7.3794

8.4336

9.4878

10.542

1100

4.4176

1.1044

2.2088

3.3132

4.4176

5.522

6.6264

7.7308

8.8352

9.9396

11.044

1150

4.6184

1.1546

2.3092

3.4638

4.6184

5.773

6.9276

8.0822

9.2368

10.3914

11.546

1200

4.8192

1.2048

2.4096

3.6144

4.8192

6.024

7.2288

8.4336

9.6384

10.8432

12.048

1250

5.02

1.255

2.51

3.765

5.02

6.275

7.53

8.785

10.04

11.295

12.55

1300

5.2208

1.3052

2.6104

3.9156

5.2208

6.526

7.8312

9.1364

10.4416

11.7468

13.052

1350

5.4216

1.3554

2.7108

4.0662

5.4216

6.777

8.1324

9.4878

10.8432

12.1986

13.554

1400

5.6224

1.4056

2.8112

4.2168

5.6224

7.028

8.4336

9.8392

11.2448

12.6504

14.056

1450

5.8232

1.4558

2.9116

4.3674

5.8232

7.279

8.7348

10.1906

11.6464

13.1022

14.558

1500

6.024

1.506

3.012

4.518

6.024

7.53

9.036

10.542

12.048

13.554

15.06

1550

6.2248

1.5562

3.1124

4.6686

6.2248

7.781

9.3372

10.8934

12.4496

14.0058

15.562

1600

6.4256

1.6064

3.2128

4.8192

6.4256

8.032

9.6384

11.2448

12.8512

14.4576

16.064

1650

6.6264

1.6566

3.3132

4.9698

6.6264

8.283

9.9396

11.5962

13.2528

14.9094

16.566

 

AUX 24V Cabling

The XT+ Extinguishant Control Panel requires that AUX 24V circuits include wire gauge and lengths specified in tables of this section.

Twin cables are connected to AUX 24V terminals of the XT+ Extinguishant Control Panel. Data provided in AUX 24V tables of this section represent resistance and voltage from a single cable-conductor. Resistance and voltage levels obtained from these tables must include the secondary conductor of the twin cable during the evaluation process.

Cable length values in the tables represent worst case conditions with the total load at the farthest point from terminals of the fire control panel.

AUX 24V tables are provided for the following recommended wire gauges:

12 AWG

1.588 Ohms / 1000 ft

14 AWG

2.525 Ohms / 1000 ft

16 AWG

4.016 Ohms / 1000 ft

12 AWG Cable

Length
(in feet)

Resistance

Voltage Drop
@ 0.1 A @ 0.2 A @ 0.3 A @ 0.4 A

100

0.15944

0.015944

0.031888

0.047832

0.063776

200

0.31904

0.031952

0.063808

0.095712

0.127616

300

0.47864

0.04796

0.095728

0.143592

0.191456

400

0.63824

0.063968

0.127648

0.191472

0.255296

500

0.79784

0.079976

0.159568

0.239352

0.319136

600

0.95744

0.095984

0.191488

0.287232

0.382976

700

1.11704

0.111992

0.223408

0.335112

0.446816

800

1.27664

0.128

0.255328

0.382992

0.510656

900

1.43624

0.144008

0.287248

0.430872

0.574496

1000

1.59584

0.160016

0.319168

0.478752

0.638336

1100

1.75544

0.176024

0.351088

0.526632

0.702176

1200

1.91504

0.192032

0.383008

0.574512

0.766016

1300

2.07464

0.20804

0.414928

0.622392

0.829856

1400

2.23424

0.224048

0.446848

0.670272

0.893696

1500

2.39384

0.240056

0.478768

0.718152

0.957536

1600

2.55344

0.256064

0.510688

0.766032

1.021376

1700

2.71304

0.272072

0.542608

0.813912

1.085216

1800

2.87264

0.28808

0.574528

0.861792

1.149056

1900

3.03224

0.304088

0.606448

0.909672

1.212896

2000

3.19184

0.320096

0.638368

0.957552

1.276736

2100

3.35144

0.336104

0.670288

1.005432

1.340576

2200

3.51104

0.352112

0.702208

1.053312

1.404416

2300

3.67064

0.36812

0.734128

1.101192

1.468256

2400

3.83024

0.384128

0.766048

1.149072

1.532096

2500

3.98984

0.400136

0.797968

1.196952

1.595936

2600

4.14944

0.416144

0.829888

1.244832

1.659776

2700

4.30904

0.432152

0.861808

1.292712

1.723616

2800

4.46864

0.44816

0.893728

1.340592

1.787456

2900

4.62824

0.464168

0.925648

1.388472

1.851296

3000

4.78784

0.480176

0.957568

1.436352

1.915136

3100

4.94744

0.496184

0.989488

1.484232

1.978976

3200

5.10704

0.512192

1.021408

1.532112

2.042816

3300

5.26664

0.5282

1.053328

1.579992

2.106656

3400

5.42624

0.544208

1.085248

1.627872

2.170496

3500

5.58584

0.560216

1.117168

1.675752

2.234336

3600

5.74544

0.576224

1.149088

1.723632

2.298176

3700

5.90504

0.592232

1.181008

1.771512

2.362016

3800

6.06464

0.60824

1.212928

1.819392

2.425856

3900

6.22424

0.624248

1.244848

1.867272

2.489696

4000

6.38384

0.640256

1.276768

1.915152

2.553536

4100

6.54344

0.656264

1.308688

1.963032

2.617376

4200

6.70304

0.672272

1.340608

2.010912

2.681216

4300

6.86264

0.68828

1.372528

2.058792

2.745056

4400

7.02224

0.704288

1.404448

2.106672

2.808896

4500

7.18184

0.720296

1.436368

2.154552

2.872736

4600

7.34144

0.736304

1.468288

2.202432

2.936576

4700

7.50104

0.752312

1.500208

2.250312

3.000416

4800

7.66064

0.76832

1.532128

2.298192

3.064256

4900

7.82024

0.784328

1.564048

2.346072

3.128096

5000

7.97984

0.800336

1.595968

2.393952

3.191936

5100

8.13944

0.816344

1.627888

2.441832

3.255776

5200

8.29904

0.832352

1.659808

2.489712

3.319616

5300

8.45864

0.84836

1.691728

2.537592

3.383456

5400

8.61824

0.864368

1.723648

2.585472

3.447296

5500

8.77784

0.880376

1.755568

2.633352

3.511136

5600

8.93744

0.896384

1.787488

2.681232

3.574976

5700

9.09704

0.912392

1.819408

2.729112

3.638816

5800

9.25664

0.9284

1.851328

2.776992

3.702656

5900

9.41624

0.944408

1.883248

2.824872

3.766496

6000

9.57584

0.960416

1.915168

2.872752

3.830336

6100

9.73544

0.976424

1.947088

2.920632

3.894176

6200

9.89504

0.992432

1.979008

2.968512

3.958016

6300

10.05464

1.00844

2.010928

3.016392

4.021856

6400

10.21424

1.024448

2.042848

3.064272

4.085696

6500

10.37384

1.040456

2.074768

3.112152

4.149536

6600

10.53344

1.056464

2.106688

3.160032

4.213376

14 AWG Cable

Length
(in feet)

Resistance

Voltage Drop
@ 0.1 A @ 0.2 A @ 0.3 A @ 0.4 A

100

0.2525

0.02525

0.0505

0.07575

0.101

200

0.505

0.0505

0.101

0.1515

0.202

300

0.7575

0.07575

0.1515

0.22725

0.303

400

1.01

0.101

0.202

0.303

0.404

500

1.2625

0.12625

0.2525

0.37875

0.505

600

1.515

0.1515

0.303

0.4545

0.606

700

1.7675

0.17675

0.3535

0.53025

0.707

800

2.02

0.202

0.404

0.606

0.808

900

2.2725

0.22725

0.4545

0.68175

0.909

1000

2.525

0.2525

0.505

0.7575

1.01

1100

2.7775

0.27775

0.5555

0.83325

1.111

1200

3.03

0.303

0.606

0.909

1.212

1300

3.2825

0.32825

0.6565

0.98475

1.313

1400

3.535

0.3535

0.707

1.0605

1.414

1500

3.7875

0.37875

0.7575

1.13625

1.515

1600

4.04

0.404

0.808

1.212

1.616

1700

4.2925

0.42925

0.8585

1.28775

1.717

1800

4.545

0.4545

0.909

1.3635

1.818

1900

4.7975

0.47975

0.9595

1.43925

1.919

2000

5.05

0.505

1.01

1.515

2.02

2100

5.3025

0.53025

1.0605

1.59075

2.121

2200

5.555

0.5555

1.111

1.6665

2.222

2300

5.8075

0.58075

1.1615

1.74225

2.323

2400

6.06

0.606

1.212

1.818

2.424

2500

6.3125

0.63125

1.2625

1.89375

2.525

2600

6.565

0.6565

1.313

1.9695

2.626

2700

6.8175

0.68175

1.3635

2.04525

2.727

2800

7.07

0.707

1.414

2.121

2.828

2900

7.3225

0.73225

1.4645

2.19675

2.929

3000

7.575

0.7575

1.515

2.2725

3.03

3100

7.8275

0.78275

1.5655

2.34825

3.131

3200

8.08

0.808

1.616

2.424

3.232

3300

8.3325

0.83325

1.6665

2.49975

3.333

3400

8.585

0.8585

1.717

2.5755

3.434

3500

8.8375

0.88375

1.7675

2.65125

3.535

3600

9.09

0.909

1.818

2.727

3.636

3700

9.3425

0.93425

1.8685

2.80275

3.737

3800

9.595

0.9595

1.919

2.8785

3.838

3900

9.8475

0.98475

1.9695

2.95425

3.939

4000

10.1

1.01

2.02

3.03

4.04

4100

10.3525

1.03525

2.0705

3.10575

4.141

4200

10.605

1.0605

2.121

3.1815

4.242

4300

10.8575

1.08575

2.1715

3.25725

4.343

4400

11.11

1.111

2.222

3.333

4.444

4500

11.3625

1.13625

2.2725

3.40875

4.545

4600

11.615

1.1615

2.323

3.4845

4.646

4700

11.8675

1.18675

2.3735

3.56025

4.747

4800

12.12

1.212

2.424

3.636

4.848

4900

12.3725

1.23725

2.4745

3.71175

4.949

5000

12.625

1.2625

2.525

3.7875

5.05

5100

12.8775

1.28775

2.5755

3.86325

5.151

5200

13.13

1.313

2.626

3.939

42

5300

13.3825

1.33825

2.6765

4.01475

5.353

5400

13.635

1.3635

2.727

4.0905

5.454

5500

13.8875

1.38875

2.7775

4.16625

5.555

5600

14.14

1.414

2.828

4.242

5.656

5700

14.3925

1.43925

2.8785

4.31775

5.757

5800

14.645

1.4645

2.929

4.3935

5.858

5900

14.8975

1.48975

2.9795

4.46925

5.959

6000

15.15

1.515

3.03

4.545

6.06

6100

15.4025

1.54025

3.0805

4.62075

6.161

6200

15.655

1.5655

3.131

4.6965

6.262

6300

15.9075

1.59075

3.1815

4.77225

6.363

6400

16.16

1.616

3.232

4.848

6.464

6500

16.4125

1.64125

3.2825

4.92375

6.565

6600

16.665

1.6665

3.333

4.9995

6.666

16 AWG Cable

Length
(in feet)

Resistance

Voltage Drop
@ 0.1 A @ 0.2 A @ 0.3 A @ 0.4 A

100

0.4016

0.04016

0.08032

0.12048

0.16064

200

0.8032

0.08032

0.16064

0.24096

0.32128

300

1.2048

0.12048

0.24096

0.36144

0.48192

400

1.6064

0.16064

0.32128

0.48192

0.64256

500

2.008

0.2008

0.4016

0.6024

0.8032

600

2.4096

0.24096

0.48192

0.72288

0.96384

700

2.8112

0.28112

0.56224

0.84336

1.12448

800

3.2128

0.32128

0.64256

0.96384

1.28512

900

3.6144

0.36144

0.72288

1.08432

1.44576

1000

4.016

0.4016

0.8032

1.2048

1.6064

1100

4.4176

0.44176

0.88352

1.32528

1.76704

1200

4.8192

0.48192

0.96384

1.44576

1.92768

1300

5.2208

0.52208

1.04416

1.56624

2.08832

1400

5.6224

0.56224

1.12448

1.68672

2.24896

1500

6.024

0.6024

1.2048

1.8072

2.4096

1600

6.4256

0.64256

1.28512

1.92768

2.57024

1700

6.8272

0.68272

1.36544

2.04816

2.73088

1800

7.2288

0.72288

1.44576

2.16864

2.89152

1900

7.6304

0.76304

1.52608

2.28912

3.05216

2000

8.032

0.8032

1.6064

2.4096

3.2128

2100

8.4336

0.84336

1.68672

2.53008

3.37344

2200

8.8352

0.88352

1.76704

2.65056

3.53408

2300

9.2368

0.92368

1.84736

2.77104

3.69472

2400

9.6384

0.96384

1.92768

2.89152

3.85536

2500

10.04

1.004

2.008

3.012

4.016

2600

10.4416

1.04416

2.08832

3.13248

4.17664

2700

10.8432

1.08432

2.16864

3.25296

4.33728

2800

11.2448

1.12448

2.24896

3.37344

4.49792

2900

11.6464

1.16464

2.32928

3.49392

4.65856

3000

12.048

1.2048

2.4096

3.6144

4.8192

3100

12.4496

1.24496

2.48992

3.73488

4.97984

3200

12.8512

1.28512

2.57024

3.85536

5.14048

3300

13.2528

1.32528

2.65056

3.97584

5.30112

3400

13.6544

1.36544

2.73088

4.09632

5.46176

3500

14.056

1.4056

2.8112

4.2168

5.6224

3600

14.4576

1.44576

2.89152

4.33728

5.78304

3700

14.8592

1.48592

2.97184

4.45776

5.94368

3800

15.2608

1.52608

3.05216

4.57824

6.10432

3900

15.6624

1.56624

3.13248

4.69872

6.26496

4000

16.064

1.6064

3.2128

4.8192

6.4256

4100

16.4656

1.64656

3.29312

4.93968

6.58624

4200

16.8672

1.68672

3.37344

5.06016

6.74688

4300

17.2688

1.72688

3.45376

5.18064

6.90752

4400

17.6704

1.76704

3.53408

5.30112

7.06816

4500

18.072

1.8072

3.6144

5.4216

7.2288

4600

18.4736

1.84736

3.69472

5.54208

7.38944

4700

18.8752

1.88752

3.77504

5.66256

7.55008

4800

19.2768

1.92768

3.85536

5.78304

7.71072

4900

19.6784

1.96784

3.93568

5.90352

7.87136

5000

20.08

2.008

4.016

6.024

8.032

5100

20.4816

2.04816

4.09632

6.14448

8.19264

5200

20.8832

2.08832

4.17664

6.26496

8.35328

5300

21.2848

2.12848

4.25696

6.38544

8.51392

5400

21.6864

2.16864

4.33728

6.50592

8.67456

5500

22.088

2.2088

4.4176

6.6264

8.8352

5600

22.4896

2.24896

4.49792

6.74688

8.99584

5700

22.8912

2.28912

4.57824

6.86736

9.15648

5800

23.2928

2.32928

4.65856

6.98784

9.31712

5900

23.6944

2.36944

4.73888

7.10832

9.47776

6000

24.096

2.4096

4.8192

7.2288

9.6384

6100

24.4976

2.44976

4.89952

7.34928

9.79904

6200

24.8992

2.48992

4.97984

7.46976

9.95968

6300

25.3008

2.53008

5.06016

7.59024

10.12032

6400

25.7024

2.57024

5.14048

7.71072

10.28096

6500

26.104

2.6104

5.2208

7.8312

10.4416

6600

26.5056

2.65056

5.30112

7.95168

10.60224

Determining the Total Load Current

The following example demonstrates the process for determining the total load current of the XT+ Extinguishant Control Panel:

  1. Identify the current draw of each device on the circuit connection.
  2. Add the device currents together in each circuit connection.
  3. Compare the sum of the device currents with the current limit of each circuit connection to verify that the summed level is below the current limit value.
  4. Add the device load currents together that were obtained for each of the circuit connections:
Circuit Connection Maximum Current Limit Example Load Current
SLC Loop 1 400 mA 150 mA
SLC Loop 2 400 mA 50 mA
AUX 24V 900 mA 0
NAC 1 2.5 A 750 mA continuous DC
NAC 2 2.5 A 925 mA continuous DC
Total Device Load 1.875 A
  1. Add the Total Device Load to the no-load alarm current to obtain the Total Load Current.
  2. Total Device Load + XT+ Extinguishant Control Panel No-Load = Total Load Current

1.875 + 200 mA = 2.075 A
Total Load Current = 2.075 A

  1. Verify that the current level is below 4 Amps: 2.075 A < 4 A
  2. This example demonstrates that device loading does not exceed the 4 Amp capacity of the power supply.

1.25 A of the 5.25 A power supply is reserved for battery charging.

Refer to Specifications for the maximum current limits provided in the example calculation above.

Determining the Standby Battery Capacity

This section provides guidelines for determining the standby battery rating. For power supply applications that do not include fire alarm equipment, alarm current is the dynamic current present during operation of the power supply. Standby current is the static current present when the power supply is not operating an alarm.

Battery Rating Equation

The equation below describes the method for determining the amp hour rating of the standby batteries:

Battery Rating = ( Battery De-Rating Factor ) x [ ( Standby amp hours ) + ( Alarm amp hours )]
OR
Battery Rating = ( Battery De-Rating Factor ) x [ ( 24 hours x Standby-Current ) + ( 5 Minutes x Alarm Current)]
where the battery de-rating factor = 1.2 and 5 minutes = 5 / 60 minutes = 1/12 = .0833 hours

To determine the amp hour rating of standby batteries:

  1. Record the standby current of the power supply.
  2. Record the standby current of the fire control panel. This current includes the LCD Main Processor Board, the Main Back Board, System A Panel Module, and System B Panel Module. It does not include current of the power supply and circuit boards in Slots C through F.
  1. Record the standby current of circuit boards populating Slots C through F.
  2. Record the standby current of SLC, NAC, and auxiliary devices.
  3. Total standby currents.
  4. Record the alarm current of the power supply.
  5. Record the alarm current of the fire control panel. This current includes the LCD Main Processor Board, the Main Back Board, System A Panel Module, and System B Panel Module. It does not include current of the power supply and circuit boards in slots C through F.
  1. Record the alarm current of circuit boards populating slots C through F of the panel.
  2. Record the alarm current of SLC, NAC, and auxiliary devices.
  3. Total alarm currents.
  4. Multiply the total standby current with the standby-time of 24, 48, or 72 hours to provide the result in amp hours.
  5. Multiply the total alarm current with the alarm time 5 or 15 minutes to provide the result in amp hours.
  6. Combine the sum of amp hours for total standby and alarm.
  7. Determine the minimum required amp hour capacity of the standby battery by multiplying the combined Amp hours with the 1.2 de-rating factor.
  8. Select a battery with a capacity rating equal or greater than the minimum required amp hour capacity determined from this calculation.

Amp Hour Rating

Complete the worksheet below to tabulate the total current load and to determine the minimum required amp hour rating of the standby batteries. Select a corresponding standby battery based on these calculations:

 

Category

Instruction

Standby Current

Alarm Current

1

Power Supply Standby Current Current of the power supply with AC input failure.

80 mA

 

2

Fire Control Panel Standby Current

Current of the fire control panel with AC input failure.

Amps

 

3

Panel Module Standby Current Current from panel modules in slots C through F with Standby and AC input failure.

Amps

 

4

External Device Standby Current

Current of SLC, NAC, and auxiliary devices with Standby and AC input failure.

Amps

 

 

5

Total Standby Current

Total all standby currents.

Amps

 

6

Power Supply Alarm Current Current of the power supply with Alarm and AC input failure.

 

80 mA

7

Fire Control Panel Alarm Current Current of the fire control panel with Alarm and AC input failure.

 

Amps

 

8

Panel Module Alarm Current Current from panel modules in slots C through F with Alarm and AC input failure.

 

Amps

 

9

External Device Alarm Current

Current of SLC, NAC, and auxiliary devices with Alarm and AC input failure.

 

Amps

10

Total Alarm Current

Total all alarm currents.

 

Amps

11

Standby Amp Hours

Multiply total standby current with 24, 48, or 72 hours to provide the result in amp hours.

Amp Hours

 

12

Alarm Amp hours

Multiply total alarm current with 5 or 15 minutes to provide the result in Amp hours:
5 minutes = .0833 hours
15 minutes = .25 hours

 

Amp Hours

13

Sum Standby and Alarm Amp Hours Combine the sum of amp hours for total standby and alarm.

Amp Hours

 

 

14

Standby Battery Amp Hour Capacity Multiply the combined amp hours with the de-rating factor of 1.2

Amp Hours

 

 

Supervising Station Requirements for Combination Systems

Due to system constraints, the use of a supervising station is required when the XT+ panel is used for providing Carbon Monoxide detection.