Installing a new furnace at a lake house in the boonies. New dedicated 12/2 NM run by electrician before I arrived. Finished install and computer in furnace was acting up so after an hour of trouble shooting I checked the ground and there was none.
Inside panel everything looked clean. No neutral double taps but buss bar was full but noticed an equipment grounding bar with one single ground landing on it. Traced back and saw it was for new furnace circuit. Tested continuity with neutral buss and it was open. Tested various KO clamps and screw holes and the panel isn't bonded. Called electrician to meet me and next day he explained how "this system is set up". There is 200 amp 3 wire feed to meter and attached pass through panel that runs 3 wire feed to two different main panels in house. House used to have two separate areas and even though now connected they are only bonded by the three wire feed. The feed tees off for each part of house. He said because of this and because the house was built in the 50's that its grandfathered in and safe.
I know now bonding and grounding is complex but it still doesn't seem safe so I called another electrician out and another day later he said basically the same. He told me if the ground was a problem for me he would switch the EGC with another one off the main buss. There is limited resources out here and I can't spend another week dealing with this.
in my business you can't make a recommendation over the phone so I understand if no one can give me advice but I was wondering if there is any issue with bonding the neutral buss with the panel. It makes perfect sense to me because it would also bond the panel and I can't fathom a reason why the NEC would allow the panel to be unbonded.
FYI I do understand current code would be to have a four wire run to each panel and have neutrals and grounds unbonded at each panel. Only bonded at the main panel but the pass though panel and two licensed electricians have me scratching my head.
Inside panel everything looked clean. No neutral double taps but buss bar was full but noticed an equipment grounding bar with one single ground landing on it. Traced back and saw it was for new furnace circuit. Tested continuity with neutral buss and it was open. Tested various KO clamps and screw holes and the panel isn't bonded. Called electrician to meet me and next day he explained how "this system is set up". There is 200 amp 3 wire feed to meter and attached pass through panel that runs 3 wire feed to two different main panels in house. House used to have two separate areas and even though now connected they are only bonded by the three wire feed. The feed tees off for each part of house. He said because of this and because the house was built in the 50's that its grandfathered in and safe.
I know now bonding and grounding is complex but it still doesn't seem safe so I called another electrician out and another day later he said basically the same. He told me if the ground was a problem for me he would switch the EGC with another one off the main buss. There is limited resources out here and I can't spend another week dealing with this.
in my business you can't make a recommendation over the phone so I understand if no one can give me advice but I was wondering if there is any issue with bonding the neutral buss with the panel. It makes perfect sense to me because it would also bond the panel and I can't fathom a reason why the NEC would allow the panel to be unbonded.
FYI I do understand current code would be to have a four wire run to each panel and have neutrals and grounds unbonded at each panel. Only bonded at the main panel but the pass though panel and two licensed electricians have me scratching my head.