how not to hook up a transformer

[e57]

A 120 solar system feeding a transformer, to feed a small panel for lighting and a few outlets, and yes an FACP....

I'll see if I can get a few pictures... But after waiting for quite some time to hook up to a stand alone solar system - the Fire Marshal was there for an Inspection - wanted the FACP powered... So I connect to what I have been very skeptical of.... Turn on some loads.... Look at the attachment - tell me what happens....

 

[dwellselectric]

Bang!:roll:

 

[iwire]

I don't see any 'bang' of the transformer.

 

[dwellselectric]

Your right iwire I was looking at the bottom where it shows the 120v line at a glance I thought it was going from 120v to ground :roll: it's to early for me I need my coffee :grin:

 

[iwire]

Mark with no bond on the bottom side those voltage measurements to ground would not exist.

 

[jumper]

I do not understand the diagram. Shouldn't there be a mid point tap XO or HO on the bottom that would be grounded? Is this an SDS, if so, where is the GEC?

 

[iwire]

Mark with no bond on the bottom side those voltage measurements to ground would not exist.

Never mind, I see the bond now.

 

[augie47]

You guys see something I don't, It appears to me the "H" side is still isolated with an output of only 240v and "floating" voltages to ground.

 

[jumper]

You guys see something I don't, It appears to me the "H" side is still isolated with an output of only 240v and "floating" voltages to ground.

I do not see it either.

 

[Smart $]

I do not see it either.

Floating loadside "neutral".

Drawn up differently...

 

[e57]

Floating loadside "neutral".

Drawn up differently...

Thank you - exactly.... The result was the FACP power supply - on FIRE.

 

[jumper]

Floating loadside "neutral".

Drawn up differently...

Thanks, that is easier to understand. Is this legal?

 

[e57]

You guys see something I don't, It appears to me the "H" side is still isolated with an output of only 240v and "floating" voltages to ground.

Yep........

 

[Smart $]

Thanks, that is easier to understand. Is this legal?

No... there is no [direct ] bond to ground of the secondary.

 

[jumper]

No... there is no [direct ] bond to ground of the secondary.

Thank you.

 

[LarryFine]

It would behave like a service with an open neutral. Stable 240v line-to-line, but line-to-"neutral" voltages would vary.

Obviously, the CT of H should be bonded.