Condo panel and transfer switch question

[HJ Gallego]

Hello all, I'm working with a 1973 condo which has a panel without a main breaker. The main is located in a locked meter room where each condo has it's own single breaker panel and meter.

The condo's panel does not have a separate ground bar like your standard subpanel and a transfer switch was installed for emergency backup power.

Since the panel does not have a ground bar the transfer switch was wired with both the neutral and ground wires to the neutral bar. What is the ruling on this type of connection?

Thanks
HJ

[Don Hawley]

Hello all, I'm working with a 1973 condo which has a panel without a main breaker. The main is located in a locked meter room where each condo has it's own single breaker panel and meter.

The condo's panel does not have a separate ground bar like your standard subpanel and a transfer switch was installed for emergency backup power.

Since the panel does not have a ground bar the transfer switch was wired with both the neutral and ground wires to the neutral bar. What is the ruling on this type of connection?

Thanks
HJ

I would say separate the grounds and neutrals if a 4 wire feed HHNG or a 3 wire feed with HHN and a metallic conduit connection to the service panel. Without either of these you will not have a source to ground so separating grounds and neutrals would make the ground wire on the branch circuits useless. As for the transfer switch I will defer to those more in the Know.

[Jerry Peck]

First question: Your description indicates that this generator would be the unit owner's generator, not an association owned generator, correct?

Second question: Your description stated "locked meter room" ... where will that unit owner's generator be placed when in use?

Third question: That main service equipment belongs to the association, not the unit owner, so I would question who permitted the transfer switch on the disconnect and does the association know it is there?

[Jim Port]

Is the transfer switch in the locked meter room with the service or is it in the condo unit?

[HJ Gallego]

Correct, the unit owner will use an electric, battery powered not gasoline generator inside their own unit only.

I don't know if the association is aware of that modification but the owner claims that he installed the transfer switch because his panel didn't have a main breaker and did not want to backfeed when using the generator.


First question: Your description indicates that this generator would be the unit owner's generator, not an association owned generator, correct?

Second question: Your description stated "locked meter room" ... where will that unit owner's generator be placed when in use?

Third question: That main service equipment belongs to the association, not the unit owner, so I would question who permitted the transfer switch on the disconnect and does the association know it is there?

- - - Updated - - -

it's inside the condo.


Is the transfer switch in the locked meter room with the service or is it in the condo unit?

[Jerry Peck]

Correct, the unit owner will use an electric, battery powered not gasoline generator inside their own unit only.

so,basically speaking, they are using a large UPS (uninterruptable power supply) ... except that it may not be connected as 'uninterruptable'?

[Jim Port]

How are they connecting the battery to the panel?

[HJ Gallego]

Yes it's basically a larger UPS connected to the transfer switch with a standard 120v 15 amp plug.

There is a black ground wire connected to the panel's case at one point but that appears to be the only ground wire used. There are no other ground wires coming from any other point into the panel, just the neutrals connected to the neutral bus bar.

Should this transfer switch have it's ground wire connected to that same point on the case instead of tied to the neutrals bar?

Thanks again

[Jim Port]

Are you saying they are using a suicide cord to connect the two?

[Jerry Peck]

Are you saying they are using a suicide cord to connect the two?

That was my thinking too.

If I understand the description correctly - the UPS is plugged into a receptacle for power to keep the batteries charged, and a suicide cord is plugged into the UPS power outlets and plugged back into a wall receptacle using a cord with two male plugs.

And, yes, I have made and used suicide cords before, but ... if you unplug the energized end ... instead of holding a safe female receptacle, you are holding an energized male plug ... one wrong slip of the hand or finger and you are grasping 120 volts!

[HJ Gallego]

Sorry I should've mentioned that it was not a suicide cord. The male end of the extension cord goes to the inverter and the female end of the cord goes to a nema 1420 adapter that plugs into the transfer switch. It's perfectly safe because there are no exposed live contacts at any time.

[John Kogel]

If the original condo wiring is in metal conduit, the panel is grounded by the nut where the conduit comes into the panel. You say there is a black wire connected to the panel case.
Usually a ground lug or bus can be installed on the back of the panel somewhere, maybe with a self-tapping screw. That sounds like what is needed here, but best to have an electrician check it out.

[HJ Gallego]

I agree, thanks for your help. :)