ETC Unison DRd Dimming Rack Enclosure User Manual
Page 55
6
Final Installation and Power Up
51
Checking the Installation before Installing Modules
It’s a good idea to look over the entire installation before installing modules or applying
power to the enclosure.
Step 1:
Clean out dust, metal scraps or other debris from the interior of the enclosure.
•
ETC recommends vacuuming the interior before installing modules.
Step 2:
Check for loose connections, bare wires and damaged insulation.
Step 3:
Manually spin the top cooling fan in both directions to be sure it is not obstructed.
Step 4:
Correct air leaks caused by misaligned or removed conduit panel openings or
empty screw holes. For complete instructions for this procedure reference
.
Step 5:
Check resistance between phases, Neutral and Earth for short circuits. With the
power connector to the Power Supply/Dimming Engine still removed (this was
accomplished prior to installing conduit and terminating any wires, see
the DRd Power Supply/Dimming Engine Access Panel, page 18
), and the all
modules removed from the enclosure, including the Station Power Module,
check resistance between phases, neutral and ground busses with a digital
voltmeter (DVM).
a: Phase to Phase; resistance should be 10M ohm or higher.
b: Phase to Earth (ground); resistance should be 10M ohm or higher.
c: Neutral to Earth (ground); resistance should be less than 1 ohm.
d: Phase to Neutral; resistance should be 10M ohm or higher.
Step 6:
Check Load Wiring. Check resistance between the load terminals and the
Neutral buss.
a: Above 1M ohm is normal when no load is connected.
b: Between 6-300 ohm is a reasonable reading when loads are connected.
c: Below 1M ohm indicates a dead short in the load wiring and an infinite
reading indicates no load or an open circuit
.
W A R N I N G :
Power must be turned OFF when you perform this procedure.
Before service, de-energize main feed to DRd and follow appropriate
Lockout/Tagout procedures as described in NFPA Standard 70E. It is
important to note that electrical equipment such as dimmer enclosures can
present an arc flash safety hazard if improperly serviced. This is due to
available large short circuit currents on the feeders of the equipment. Any
work on energized equipment must comply with OSHA Electrical Safe
Working Practices.
C A U T I O N :
A dead short can cause module damage.