Motor Heater Shunt?

[icesoft]

Is the copper strap across the terminals on the overloads normal, or is it someone's attempt to stop nuisance tripping? First time I've seen one like this, as I'm more familiar with the melting alloy type OL Heaters.

 

[jim dungar]

Is the copper strap across the terminals on the overloads normal, or is it someone's attempt to stop nuisance tripping? First time I've seen one like this, as I'm more familiar with the melting alloy type OL Heaters.

Not normal.

Does not look like it came from a manufacturer.
The only time I have seen an 'approved' overload jumper was for a standard 3-phase OL block being used on a 1-phase circuit.

 

[LarryFine]

Yep, it's a shunt, and renders the overload sensing useless.

 

[Cold Fusion]

Is the copper strap across the terminals on the overloads normal, or is it someone's attempt to stop nuisance tripping? First time I've seen one like this, as I'm more familiar with the melting alloy type OL Heaters.

Were all three or even two phases like that - or just one?

It was somewhat popular in the 60s/early 70s to use corner grounded 240D and I've even seen a few corner grounded 480D. For corner grounded services, the code did not used to require that all three phases have an overload.

Not common, but there are likely a few cases still out there.

cf

 

[jim dungar]

Were all three or even two phases like that - or just one?

It was somewhat popular in the 60s/early 70s to use corner grounded 240D and I've even seen a few corner grounded 480D. For corner grounded services, the code did not used to require that all three phases have an overload.

Not common, but there are likely a few cases still out there.

cf

Actually up until the early 60's, no 3-phase starter was required to have OL in each leg. Starters only came with (2) OL's.