Installation guide

Wiring
975-0540-01-01 Revision B 2–11
This guide is for use by qualified personnel only.
Over-current Protection
If a fuse is used for over-current protection, a disconnect switch must also be
provided between the fuse and the source of supply (the PV array or the battery).
If a circuit breaker is used, it will serve both purposes of disconnection and over-
current protection.
Battery Circuit For installations in the United States, the NEC requires that the battery circuit be
protected with a device rated for 125% of the rating of the circuit. The DC-rated
fuse or circuit breaker between the battery and the charge controller must be
rated—at minimum—100 A and must not exceed the allowable over-current
protection rating for the size of wire being used, in accordance with applicable
electrical codes.
PV Circuit A properly rated PV disconnect switch is mandatory between the PV array and
the charge controller, and it must be rated for 600 VDC and have a sufficient
current rating for your specific installation.
For installations with three or more PV array strings connected to one charge
controller, each string must be fused before being combined at the PV input
terminal connector inside the wiring compartment. See “Connecting Multiple PV
Array Strings to One Unit” on page 2–14 for more information.
You can use separate disconnect switches for each PV string and combine these
in the charge controller, as long as the following conditions are met:
• Each PV string is fused.
• All disconnects are placed side by side, so that it is clear that all need to be
thrown for a complete and visible PV disconnect.
WARNING
HAZARD OF ELECTRIC SHOCK, ENERGY, AND FIRE
Over-current protection must be provided, external to the unit, to protect the
PV and battery wiring. External disconnecting means must also be provided
for the PV and battery circuits. Consult local electrical codes to establish the
correct fuse or circuit breaker ratings and for required locations of protection
and disconnecting means.
Failure to follow these instructions can result in death or serious injury.
DANGER
HAZARD OF ELECTRIC SHOCK
The PV disconnect switch can only be installed safely if the array is covered
securely with an opaque (dark) material.
Failure to follow these instructions will result in death or serious injury.