February 2011 A-4 P/N 06-237041-001
A-3 CALCULATING POWER SUPPLY NEEDS
Use Tables A-3 through A-4 to determine power supply configuration needs.
Note: Amount of current with dead front cover in place shown in parentheses.
Note: Amount of current with dead front cover in place shown in parentheses.
A-4 FOR INSTALLATIONS IN CANADA
For panels installed in Canada, the charger must replace 70-percent of the used battery capacity within
12 hours per ULC S527.
Referring to our earlier example, since the total ampere hours of battery to be used is equal to 9.88,
the system’s PSUs must re-charge 9.88 x .70 AH (6.92 AH) back into the battery within 12 hours for
compliance with ULC S527. In our example, which includes two power supply units, the available
charging current is equal to 8 A maximum. Therefore, the system can supply 8A x 12 hours or 96-AH
and will meet ULC requirements.
Table A-3. Minimum Power Supply Requirements for 3-Tiered Enclosure
Number of
Power Supply Units
Charging Current
Available
Total Alarm Current
1 4 A 5.4 A
2 8.9 A 10.8 A
3 8.9 A 12 A
4 8.9 A 16 A
5 8.9 A 20 A (17 A)*
6 8.9 A 20 A (17 A)*
Table A-4. Minimum Power Supply Requirements for 2-Tiered Enclosure
Number of
Power Supply Units
Charging Current
Available
Total Alarm Current
1 4 A 5.4 A
2 8.9 A 10.8 A
3 8.9 A 15 A (11 A)*
4 8.9 A 15 A (11 A)*