Page 133 - Alternative Energy Systems in Building Design

SOLAR POWER SYSTEM WARNING SIGNAGE 109

When measuring electric current and voltage output values of a solar power module,
short-circuit current (I ) and open-circuit voltage (V ) values must be compared with
oc
sc
the manufacturer’s product specifications.
To obtain the I value, a multimeter amperemeter must be placed between the
sc
positive and negative output leads, shorting the module circuit. To obtain the V reading,
oc
a multimeter voltmeter simply should be placed across the positive and negative leads
of the PV module.
For larger current-carrying cables and wires, current measurements must be carried
out with a clamping meter. Since current-clamping meters do not require circuit opening
or line disconnection, different points of the solar arrays could be measured at the same
time. An excessive differential reading will be an indication of a malfunctioning array.
It should be noted that when a PV system operates at the startup and commissioning,
it is seldom that problems result from module malfunction or failure; rather, most mal-
functions result from improper connections or loose or corroded terminals.
In the event of a damaged connector or wiring, a trained or certified technician should
be called on to perform the repairs. Malfunctioning PV modules, which are usually guar-
anteed for an extended period of time, should be sent back to the manufacturer or
installer for replacement.
Please be cautioned not to disconnect dc feed cables from the inverters unless the entire
solar module is deactivated or covered with a canvas or nontransparent material. It is rec-
ommended that roof-mounted installations should have 3/4-in water hose bibs installed at
appropriate distances to allow periodic washing and rinsing of the solar modules.

Solar Power System Warning Signage

For a solar installation system:

Electric shock hazard—Do not touch terminals—Terminals on both line and load sides may be
energized in open position.

For switchgear and metering system:

Warning—Electric shock hazard—Do not touch terminals—Terminals on both the line and load
side may be energized in the open position.

For pieces of solar power equipment:

Warning—Electric shock hazard—Dangerous voltages and currents—No user-serviceable parts
inside—Contact qualified service personnel for assistance.

For battery rooms and containers:

Warning—Electric shock hazard—Dangerous voltages and currents—Explosive gas—No
sparks or flames—No smoking—Acid burns—Wear protective clothing when servicing typical
solar power system safety warning tags.