Alpha Technologies Rear Access Bullet Breaker Panel, 19 - Manual (Page 12)

Argus Technologies Ltd. 020-671-C0 Rev A WC
Printed in Canada. © 2007 Argus Technologies Ltd. ARGUS is a registered trademark of Argus Technologies Ltd. All Rights Reserved. Page 4 of 7
4 Wiring and Connections
This chapter provides cabling details and notes on cable sizing for DC applications.
NOTE: Refer also to foldout drawings located at the rear of the manual.
4.1 Safety Precautions
WARNING
Hazardous AC voltages may be present. Ensure power at the AC service panel is off before
attempting work on the AC connections. Use a voltmeter to verify the absence of voltage. Clearly
mark the correct polarity of the battery leads before commencing work on DC connections.
Refer to the previous (Installation) chapter for additional safety precautions.
4.2 Calculating Output Wire Size Requirements
Wire size is calculated by first determining the appropriate maximum voltage drop requirement. Using the formula
below calculate the CMA wire size requirement. Determine the size and number of conductors required to satisfy
the CMA requirement.
CMA = (A x LF x K) / AVD, where:
CMA = Cross section of wire in circular mil area
A = Ultimate drain in amps
LF = Conductor loop feet
K = 11.1 constant factor for commercial (TW type) copper wire
AVD = Allowable voltage drop
Check again that the ampacity rating of the cable meets the requirement for the installation application. Consult
local electrical codes (NEC, CEC, etc.) for guidelines. If required, increase the size of the cable to meet the code.
4.3 System and Load Connections
WARNING
Leave cables or bus bars disconnected at battery and verify output polarity using a voltmeter.
Make battery connections only after all other wiring is completed.
DC output wire shall be UL approved XHHW or RHH/RHW (for Canadian users, RW90 Type).
Connect DC system and load cables at the rear of the distribution panel (refer to customer connection drawing).
Figure 2–Rear view of typical panel showing system and load connections
3/8” x 1” center
for bus bar or
wire lug connection Typical
1/4" x 5/8” centers
for up to #2 wire