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For troubleshooting, call technical assistance at 1-800-237-4567 or [email protected]
10
IO-70061
01/2020
ASCO 430 Surge Protective Device (SPD)
System Grounding
Figure 3:
SPD Wiring for Delta Configurations
To load(s)
Phases
Ground
Phase A
Phase B
Phase C
Ground
SPD
Interconnect wiring
– Minimize length
– Avoid sharp bends
HAZARD OF ELECTRIC SHOCK, EXPLOSION, OR ARC FLASH
• Ungrounded power systems are inherently unstable and can produce
excessively high line-to-ground voltages during certain electrical
fault conditions. Durign these electrical fault conditions any electrical
equipment, including a surge protective device, may be subjected to
voltages which exceed their designed ratings.
• Make an informed decision before installing any electrical equipment on
an ungrounded power system.
Failure to follow these instructions will result in death or serious
injury.
NOTICE
LOSS OF SURGE SUPPRESSION
• Verify that the service entrance equipment is bonded to ground in
accordance with all applicable codes.
Failure to follow these instructions can result in equipment damage.
The ASCO 430 has SPD elements connected from phase to ground. It
is critical that there be a robust and effective connection to the building
grounding structure. The grounding connection must utilize an equipment
grounding conductor run with the phase and neutral connection of the
power system. Do not connect the SPD to a separate isolated ground.
For proper voltage suppression by the ASCO 430 SPD, use a single-point
ground system where the service entrance grounding electrode system is
connected to, and bonded to, all other available electrodes, building steel,
metal water pipes, driven rods, etc. (for reference, see NEC Art 250). The
ground impedance measurement of the electrical system must be as low as
possible and in compliance with all applicable codes for sensitive electronic
and computer systems.
System Grounding
DANGER
