Let me state my observations first and then I have ONE main question…but maybe more as I’m sure this topic will grow many heads as always I’ll try to keep it simple but there were many moving parts and my intent is to learn on each and every inspection.
I inspected a 1977 single family home in Los Gatos, CA today. The home had an original Zinsco main with a solar upgrade (roof panels) and storage batteries (Enphase system) and a Siemens subpanel 4-wire MLO (thanks! @ rmeier2) adjacent to and downstream from the main. The main panel was labeled “Sylvania” and the 200A disconnect was a Zinsco labeled breaker. The Siemens subpanel had a downstream Homelite subpanel 4-wire MLO in the crawlspace behind the aforementioned main & sub as well without the neutrals and grounds separated. Edit: I will be noting in my report that the neutrals and EGC’s shall be separated in a subpanel and that having them bonded is a defective condition.
The Zinsco had a 200A disconnect from the SE labeled as such. Below the 200A disconnect is a 125 OCPD which appeared to be wired through the Enphase solar panel enclosure and then into the upgraded Siemens subpanel.
I will be recommending that a licensed electrician evaluate the Sylvania/Zinsco panel for the same reasons that some of us typically do and this is not the reason for my post.
My observation and question is that I observed individual branch circuits connected to OCPD’s on the Zinsco main panel which used both black and white wires for the live/hot branch circuits connected to the OCPD’s but I did not see any neutral wires connected to the bonded neutral/EGC buss. Why are there no apparent neutrals visible, present, nor bonded to the Neutral/EGC buss in the main (edit: with the exception of one visible neutral connected at the buss)? Is there an allowance within a solar installation upgrade that allows this main panel neutral/EGC bonding to occur somewhere else or not at all?
And yes, I will comment on the white wires being used as live/hot wires not being marked as hot
I have lots of pics! I will post some and please let me know if you need more for clarification.
Yes, it appears they are so that would explain it. So then, are those handle ties (aluminum sleeve) on every other breaker for a 240v circuit? I guess I’m unfamiliar with how Zinsco breakers tie the handles together for a 240v circuit.
A bit confused… where are the neutrals for the 240-V circuits fed by the Zinsco panel? I thought that all 240-V circuits within residences require neutrals?
I know a few solar installers and none of them would ever consider installing a solar system with a Zinsco panel, though I have seen it anyway.
Not only would I call out the Z panel, and the other things you have already observed, I’d call out the entire installation for being non-professional just for good measure.
The 240v equipment in this home that you’re asking about such as baseboard heaters, wall heaters, and water heaters don’t require a neutral. Only equipment that also requires 120v would need the neutral such as a dryer.
Edit: I meant to include this simple explanation that I found on an electrical forum:
In a 120/240 Volt Single Phase system, the transformer secondary coil is “center tapped” to ground which defines the grounding conductor’s voltage as “zero”. The right and left extremes of the secondary coil are the taps for each 120 Volt leg. Voltage from either the right or left tap to the grounded center tap will be 120 Volts or thereabouts. But the voltage between the left and right taps are 240 Volts, not involving the grounded conductor at all.
Some circuits are considered 120/240 Volt. Your Dryer, Range, and the service for your house fit this description. These contain a grounded conductor as well as two hot conductors. This is to provide a grounded conductor for motors, timers and buzzers that operate at 120 Volts. Usually the heating element is the only 240 V draw on a dryer. Water heaters only require a “straight” 240 Volt circuit.
Here is one video that explains this in a good demonstrative way.
David’s video (above) explains it really well. The neutral balances the load. Some simple 240-V appliances work just fine with no neutral, such as a motor, because they are naturally balanced. However, more complicated (unbalanced) appliances that incorporate 120-V components, such as furnace or clothes dryer will suffer poor performance or experience failures from an unbalanced load, and therefore, need a neutral.
He’s lucky that the lamp didn’t explode in his face when he put over 170 volts across it. The reason that certain 240 volt equipment needs a neutral is because part of the equipment operates at 120 volts it has little to do with performance.
I’ll try to keep it simple but there were many moving parts and my intent is to learn on each and every inspection.
