Transfer Switch

[jap]

I came across a Xfr Switch installation where they had taken a 400 amp Meter combo unit with (2) 200 amp Main Breakers.
They had taken the jumpers out from the load side of the meter in to the line side of the 200a breakers. Nippled a 400a Transfer switch next to this Combo unit, Wired from the Load side of the meter in the combo unit to the line side of the Xfr switch and from the Xfr switch back to the line side of the 200a breakers.

Was taking the Jumpers out from the load side of the meter in the Factory Combo unit a violation?

 

[augie47]

Sounds like altering a piece of UL listed equipment which voids that listing. How the local AHJ views it varies fork jurisdiction to jurisdiction. I would also question if the 400 amp transfer was switch rated as service equipment ? Does it have a main overcurrent device ?

 

[jap]

it does not.

 

[augie47]

Then the alteration is somewhat of a mute point.
230.82 will not permit a transfer switch that is not rated as service equipment to be placed ahead of the service disconnects.
(To my knowledge any transfer switch rated for service equipment will have overcurrent protection)

 

[suemarkp]

To my knowledge any transfer switch rated for service equipment will have overcurrent protection

Not true. It is permitted to have the overcurrent "immediately adjacent" to the transfer switch. I have a Cutler-Hammer manual transfer switch, and it does not have integral overcurrent protection but does have the Suitable for use as Service Equipment labeling.

This could be a valid install. Still need to know if the xfer switch has a SUSE label. I can't judge whether the jumper mods violate a UL listing -- probably an AHJ question.

If the transfer switch and meter cabinets are different, the main bonding jumper need to be at the transfer switch and the neutral isolated at that point. So could be an issue there too, but perhaps they'll treat this as one giant piece of Service Equipment.

 

[augie47]

Mark, Correct. I ass-u-me-d that is was an automatic transfer switch, not a manual.

 

[RUWired]

Another question for the OP is did the grounded conductor get routed to the transfer switch and back to the lower half of the combo. Could be a 230.75 violation as well if not.

 

[LarryFine]

Another question for the OP is did the grounded conductor get routed to the transfer switch and back to the lower half of the combo. Could be a 230.75 violation as well if not.

If the conductors in both directions share the same raceway, there's no concern (unless the switch needs the neutral.)

If the genny feeds the TS enclosure, its neutral needs to be in there.

 

[jap]

A neutral was run from the loadside of the Meter to the xfr switch through a
2" rigid nipple, then a neutral was ran return from the Transfer switch with the 2 hots back to the Combo through a 2nd 2" rigid nipple.

 

[augie47]

manual or automatic transfer switch ?