GE Industrial Solutions Evolution Switchboards - Manuel (Page 9)

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Chapter 2- Installing the Switchboard
99
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Switchboards are furnished with medium carbon steel
hardware with the tensile strengths listed in Table 1.
Similar hardware must be used for any additional
bolting. Use a torque wrench when tightening to the
nominal values given, for either copper or aluminum
connections. Use flat and lock washers for all
connections. Do not place washers under the heads of
carriage bolts.
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1/4-20 120,000 4
5/16-18 120,000 9
3/8-16 120,000 16
1/2-13 60,000 39
1/2-13 with/avec
21/4" Belleville
washer/rondelle
60,000 70
5/8-16 60,000 80
TTaabbllee 11. Tightening torques for supplied hardware.
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Maintain the minimum clearances listed in Table 2 (UL) and
Table 3 (CSA) except at terminals of circuit breakers and
switches.
C Coonnddiittiioonn
VVoollttaaggee D Diiffffeerreennccee
D Diifffféérreennccee ddee tteennssiioonn
00––112255 VV 112266––225500
VV
225511––660000
VV
Between un-insulated
live parts of opposite
polarity
Through air
Over surface
1/2" [13]
3/4" [19]
3/4" [19]
11/4" [31]
1" [25]
2" [51]
Between un-insulated
live parts and grounded
metal through air or
over surface
1/2" [13] 1/2" [13] 1" [25]
TTaabbllee 22.. Minimum clearances for live parts (UL).
A through-air spacing of not less than ½ inch is acceptable
at a circuit breaker or a switch, other than a snap switch,
and between grounded dead metal and insulated neutral of
a 277/480 VAC three-phase, four-wire panel board or
switchboard.
TTaabbllee 33.. Minimum clearances for live parts (CSA).
Where neutral to phase is involved, spacing may be based
on the normal voltage between them. Neutral-to-ground
spacing’s should be based on the same spacing’s required
for the other conductors.
C Coonnddiittiioonn
VVoollttaaggee D Diiffffeerreennccee
00––112200 VV 112211––224400
VV
224411––448800
VV
448811––660000
VV
Between un-insulated
live parts of opposite
polarity
Through air
Over surface
1/2" [13]
3/4" [19]
3/4" [19]
11/4" [31]
7/8" [22]
13/4" [44]
1" [25]
2" [51]
Between live parts and
ground
Through air
Over surface
1/2" [13]
3/4" [19]
3/4" [19]
1" [25]
7/8" [22]
11 1/32"
[34]
1" [25]
11/2" [38]