Donald Hester
Washington State Licensed Home Inspector #647
WSDA#80050
InterNachi Member #NACHI10022401
509-670-9572
Contact Us
Washington State Licensed Home Inspector #647
WSDA#80050
InterNachi Member #NACHI10022401
509-670-9572
Contact Us
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Shared Neutrals (grounded conductors)- Not such a good Idea?
Submitted by DonHester on Sat, 07/04/2015 - 10:08.
Shared Neutrals (grounded conductors)- Not such a good Idea? Wenatchee Home Inspections
Shared neutrals are common on Multiwire Branch Circuits (MWBC) but is a practice that I am not really fond of (along with backstabbed receptacles) nut is totally code acceptable.
Here is a little information from Square D-
Serious Disadvantages to Sharing Neutrals-
The practice of shared neutrals may seem attractive due to possible savings
associated with the reduction of a neutral conductor. However, there are
serious disadvantages to sharing neutrals:
• If the shared neutral is lost, the connected loads are subject to
voltages varying from 0 to 240 V (line-to-line). This is especially true if
one load has much larger impedance than the other. The likely result
from this is severe damage to some connected devices due to extreme
under- and over-voltage conditions. See Figure 5.
• On two-pole common-trip circuit breakers, both circuits are interrupted
during any type of fault. If a shared neutral circuit feeds two rooms, then
both rooms lose power if a fault occurs in either. If a shared neutral
circuit feeds receptacles and lights, both will lose power with a fault on
either one.
• On two-pole independent-trip circuit breakers, one may find hot wires
in a junction box that was presumed dead. One cannot overemphasize
how dangerous this would be. If one of the shared neutral circuits were
to trip due to a short-circuit or overload, the other circuit would remain
hot. Anyone servicing any device in that junction box may be exposed to
live conductors.
Remember codes are minimum standards and as such in some areas, though code acceptable, it may not be the best practice.
“The bitterness of poor quality remains long after the sweetness of low price is forgotten.”
Benjamin Franklin
NCW Home Inspections, LLC is a Licensed Washington State Home Inspection service located in Wenatchee Washington serving Chelan County, Douglas County, Kittitas County, Okanogan County and Grant County Washington and the cities of Wenatchee, Leavenworth, Cashmere, Oroville, Cle Elum, East Wenatchee, Quincy and many more…
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