3 phase 4 wire logging

[Krusscher]

I'm trying to hook my fluke 1735 up to a 3 phase 4 wire delta 240/120 panel but it doesn't seem to have a setting for that. Also when I set it up just to read like a 3 wire delta it's not reading any voltage between 1 and 3. So I checked it with my meter and it only reads between 1 and 3 on the 3 pole breakers in the top of the panel.

 

[Krusscher]

I think they may have only used the wild leg in the top 9 slots and used 1 and 3 for the rest. I have never seen this done but then again I don't see too many 4 wire deltas either.

 

[acrwc10]

I think they may have only used the wild leg in the top 9 slots and used 1 and 3 for the rest. I have never seen this done but then again I don't see too many 4 wire deltas either.

It looks like you are correct, there is no 3rd phase in the lower half of the bussing, you can see it's not there.

 

[jim dungar]

I think they may have only used the wild leg in the top 9 slots and used 1 and 3 for the rest. I have never seen this done but then again I don't see too many 4 wire deltas either.

This was a common Square D construction back in the pre-90s. It increased the amount of 1P breaker spaces and reduced the likelihood of putting a single phase load on the high leg.