Garage sub panel

[gpglinka]

I know little about panel boxes. Garage light went out, bulb ok, seemed to be panel box. Box is round fuse type so I figured it should be replaced. Disconnected it and touched feed wires to circuit wires and the light didn't come on. Connect feed wires to and outlet circuit that has fluorescent light, and it hummed and was so bright. The circuit that has the light in it also has an outlet. I plugged a fan in and that sped fast but the light still wasn't on. The feed wires read 250 amps. Is it thpanel box that splits t he amp for a 120 circuit.

 

[Snoonyb]

A panoramic photo would be enlightening.

Presumably, the feed conductors enter the panel on the right side, (NOT SHOWN), and how many conductors are in the feed?

Do you have a VOM, (VOLT, OHM METER)?

 

[gpglinka]

There are black and white and ground. Yes have meter

 

[Snoonyb]

So, 2 hots & a grnd., but no neutral, or is, what you are calling a grnd., used as the neutral?

Is the grnd. conductor bare or encased, and are the feeds encased, or separate, free floating.

 

[gpglinka]

Bare ground wire.

 

[gpglinka]

There is 60 amp breaker in house main panel that feed the barn, garage and two out buildings

 

[Snoonyb]

Do all 3 have sub-panels, fed similarly?

So, when you meter between the 2 bottom terminal lugs, on the sub-panel, you read 240V?

 

[gpglinka]

The black and white wires read 250 amps

 

[Snoonyb]

The black and white wires read 250 amps

What type of meter are you using to measure current?

I had asked about voltage, in measuring between the terminal lugs in the sub-panel.

 

[gpglinka]

Klein mm300 The bare wires read 250 amps. Volts don’t give reading.

 

[gpglinka]

Okay. Meter running right now. 240 volts on bare black and white wires

 

[gpglinka]

Old panel is corroded. Need to replace

 

[Snoonyb]

Okay. Meter running right now. 240 volts on bare black and white wires

You have a dangerous system, because the grnd. is a voltage conductor and should only be used as a safety device.

If the appliances you connected both the black & white conductors too, are not labeled 240V, 277V or 208V, then prolonged connection, as stated, will cause them to fail.

So, for those appliances to function, with your existing system, you can connect with the black or white conductors, not both, to the black lead on the appliance, then the white of the appliance to the copper grnd.

 

[gpglinka]

Why is ground a conductor? Can I connect new 60 amp box and use one side of it? Old box had one 30 amp fuse in it.

 

[Snoonyb]

Well, in post #1, you said that there were two, 120V circuits, and for that to be true, the grnd. had to have been being used as a neutral, because, by definition a 120V circuit is a hot and a neutral, and hopefully a grnd.

I think that you will find that a modern 60A sub-panel will have a 4 conductor feed, 2-hots, a neutral and a grnd, and the connections at your service will need to be updated to reflect the change.

 

[gpglinka]

Just checked outlets, switches and light and the ground is used as ground. Don’t know how feed ground was wire in panel.

 

[Snoonyb]

That could appear to be true, if the grnd. in the sub-panel is attached to the neutral buss bar in the service panel.

Please describe the method you used to determine that.

 

[gpglinka]

Opened boxes and looked at where ground was attached on switches, outlets and light.

 

[Eddie_T]

If there is no need for 240v the feed it could be converted to 120v at the main panel to solve the wiring problem.

 

[Snoonyb]

Opened boxes and looked at where ground was attached on switches, outlets and light.

AND............?