jar546
Forum Coordinator
On this transformer, based on the grounding and bonding method chosen, would the first means of disconnect on the secondary side of this transformer have the neutrals and grounds separated or tied together?
-
Welcome to the new and improved Building Code Forum. We appreciate you being here and hope that you are getting the information that you need concerning all codes of the building trades. This is a free forum to the public due to the generosity of the Sawhorses, Corporate Supporters and Supporters who have upgraded their accounts. If you would like to have improved access to the forum please upgrade to Sawhorse by first logging in then clicking here: Upgrades
Transformer bonding and the first means of disconnect
- Thread starter jar546
- Start date
jar546
Forum Coordinator
No one does electrical inspections?
ICE
Oh Well
Is there a secondary neutral? GECs and EGCs should not be routed through lay-in lugs on bushings.
This kind of stuff is above my level of expertise. I have inspected maybe five transformers in twenty-five years. The covers were still on and the vibration noise had me convinced that the transport springs were removed. Nothing blew up and I didn’t see any blood stains. Let me be the first to state that I had no business doing the inspection… there I beat you to the punch.
So with your picture I can just take a shot in the dark. I see phases with a neutral coming in but not going out. While that seems odd ... who knows, it could be as normal as carp in the Rock River. Maybe I’ve got it all wrong and it’s a step up with no neutral coming in.
Your question is about tying the neutral and ground at the secondary disconnect. Hard to know without exploring the NEC. If the primary has a bonded neutral and the secondary shares the neutral I’m leery of a secondary bonded neutral. But hey now I can be all over the map with this because it will never be in my wheel house.
I could delve into the NEC and find an answer… or you could take the step to educate us. I for one, would be happy to learn from you.
This kind of stuff is above my level of expertise. I have inspected maybe five transformers in twenty-five years. The covers were still on and the vibration noise had me convinced that the transport springs were removed. Nothing blew up and I didn’t see any blood stains. Let me be the first to state that I had no business doing the inspection… there I beat you to the punch.
So with your picture I can just take a shot in the dark. I see phases with a neutral coming in but not going out. While that seems odd ... who knows, it could be as normal as carp in the Rock River. Maybe I’ve got it all wrong and it’s a step up with no neutral coming in.
Your question is about tying the neutral and ground at the secondary disconnect. Hard to know without exploring the NEC. If the primary has a bonded neutral and the secondary shares the neutral I’m leery of a secondary bonded neutral. But hey now I can be all over the map with this because it will never be in my wheel house.
I could delve into the NEC and find an answer… or you could take the step to educate us. I for one, would be happy to learn from you.
Last edited:
jar546
Forum Coordinator
chris kennedy
Sawhorse
EGC bonded to neutral in secondary disconnect. Notice anything odd about the GEC?
steveray
SAWHORSE
I thought there was something about attaching the grounding over the slots in the bottom, but took a quick look and couldn't find it....Hate that book...Looks like it is cut/ broken...
jar546
Forum Coordinator
Oh, and in addition to the question in the OP, there are some issues too. What are they.
wwhitney
Registered User
Why not? Seems perfectly normal to me. If a GEC is contained in a metal conduit, it needs to be bonded to the metal conduit at both ends, and running it through a grounding bushing would be one way to do that. And EGCs and bonding jumpers get connected to metal conduit all the time, with a grounding bushing being one way to do it.
Cheers, Wayne
ICE
Oh Well
The resulting sharp bends. If enough current hits the bend, it will blow out.
250.4(A)(1) Electrical System Grounding.
Electrical systems that are grounded shall be connected to earth in a manner that will limit the voltage imposed by lightning, line surges, or unintentional contact with higher-voltage lines and that will stabilize the voltage to earth during normal operation.
Informational Note No.1: An important consideration for limiting the imposed voltage is the routing of bonding and grounding electrode conductors so that they are not any longer than necessary to complete the connection with out disturbing the permanent parts of the installation and so that unnecessary bends and loops are avoided.
Last edited: