Calculating the System Current Draw

Power Supply Calculations

Table 5-3 contains three columns for calculating current draws. For each column, calculate the current and enter the total (in amperes) in the bottom row. When finished, copy the totals from Calculation Column 2 and Calculation Column 3 to Table 5-4 on page 102.

TABLE 5-3:System Current Draw Calculations

 

Calculation Column 1

 

 

Calculation Column 2

 

Calculation Column 3

 

Device Type

Primary, Non-Fire Alarm Current

 

Primary, Fire Alarm Current

 

Secondary, Non-Fire Alarm Current

(amps)

 

 

 

 

(amps)

 

 

 

(amps)

 

 

 

 

Qty

 

X[current draw]=

Total

 

Qty

X [current draw] =

Total

 

Qty

X[current draw]=

Total

 

 

 

 

 

 

 

 

 

 

 

 

 

Main Circuit Board

1

 

X[0.122]=

0.122

 

1

X[0.185]1=

0.185

 

1

X[0.122]=

0.122

CAC-5X

[

]

X[0.001]=

 

[

]

X[0.001]=

 

[

]

X[0.001]=

 

 

 

 

 

 

 

 

 

 

 

 

 

 

4XTMF

[

]

X[0.005]=

 

[

]

X[0.011]1=

 

[

]

X[0.005]=

 

ANN-80

[

]

X[0.037]=

 

[

]

X[0.040]=

 

[

]

X[0.037]=

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2-wire Detector Heads

[

]

X[

]2=

 

[

]

X[

]=

 

[

]

X[

]=

 

4-wire Detector Heads

[

]

X[

]2=

 

[

]

X[

]=

 

[

]

X[

]=

 

Power Supervision

[

]

X[0.025]=

 

[

]

X[0.025]=

 

[

]

X[0.025]=

 

Relays3

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

NAC #14

 

 

 

 

 

[

]

X[

]=

 

 

 

 

 

 

NAC #2

 

 

 

 

 

[

]

X[

]=

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

NAC #3

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

NAC #4

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Current Draw from

 

 

[

]=

 

 

 

[

]=

 

 

 

[

]=

 

TB9 (nonalarm5)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Sum each column6

Primary Non-Alarm =

 

 

Primary Alarm =

 

 

Secondary Non-Alarm =

 

for totals

 

 

 

 

 

Table Footnote

1.If using the Reverse Polarity Alarm output, add 0.005 amps; if using the Reverse Polarity Trouble output, add another 0.005 amps.

2.Refer to the Device Compatibility Document for standby current.

3.Must use compatible listed Power Supervision Relay.

4.Current limitation of Terminal TB5 circuits is 3.0 amps per NAC

5.The total standby current must include both the resettable (TB9 Terminals 3 & 4) and nonresettable/resettable (TB9 Terminals 1 & 2) power. Caution must be taken to ensure that current drawn from these outputs during alarm does not exceed maximum rat-

ings specified. Current limitations of TB9, Terminals 1 & 2 = 0.500 amps, filtered, 24 VDC +/-5%, 120 Hz ripple @ 10 mVRMS, nonresettable power and TB9, Terminals 3 & 4 = 0.500 amps, filtered, 24 VDC +/-5%, 120 Hz ripple @ 10mVRMS, resettable power.

6.Total current draw listed above cannot exceed 7.0 amps

MRP-2001 & MRP-2001E PN 53040:A 4/16/2007

101