Clearance behind MV switch gear
- Thread starter faresos
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SG-1
Senior Member
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- Ware Shoals, South Carolina
How wide are the structures & do they have hinged doors or bolted on covers ?
Hameedulla-Ekhlas
Senior Member
- Location
- AFG
Per Section 110.34(A)(1) notes that workiing space is not required behind dead-front equipment when there are no fuses, switches, other parts, or connection requiring rear access. but the rule adds that if rear access is necessary to permit work on deenergised parts of the enclosed assembly, the work space must be at least 30 inch.
it's unit substations, (3)36" sections for MV breakers, 2500/3333KVA XFMR and low voltage distribution and ties (Double-Ended), Total of aprx. 44ft.
SG-1
Senior Member
- Location
- Ware Shoals, South Carolina
If the rear panels swing and are 36 inches wide and have stops they could prevent egress when opened.
Hameedulla-Ekhlas
Senior Member
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- AFG
SG-1
Senior Member
- Location
- Ware Shoals, South Carolina
We are in agreement.
weressl
Esteemed Member
There are - or could be - live components in the rear, so in that case the access rules based on voltage should be followed as per Table 110.34(A) Minimum Depth of Clear Working Space at Electrical Equipment.
There are fused switches and MV motor starters that are dead front, but most switchgears require both front and access. It even could be argued that in the case of switchgears most do NOT provide access to live parts from the front - if you have shutters - but the cable landings are accessible from the rear. In that case you could apply the minimum 30" to the front and the table for the rear. Door swing or the withdrawal depth requirement may exceed that though.
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