I am connecting a portable generator to my electric sub-panel in my garage. My generator is a 6kw running watt unit with a 30amp 220 volt output. I will be using this connection (L14-30) to a box outside my garage. This box will be connected to a shut-off panel inside the garage. This shut-off panel will be connected to the sub-panel, via a 30 amp double pole breaker (220 volt). I would like to measure each leg for volts, amps and watts. Am I correct in that I can measure each (2)"hot" wire for volts, and amps, or do I need to include the "common" wire and add the amps from that for my total? I also want to keep an eye on the total running watts from each leg to keep from overloading the generator. I may need to remove some devices as they start, because of their starting current.
I am not using an automatic transfer switch, so I will be shutting off the Main breaker before I start the generator. I will then shut off ALL breakers, before I switch the shut-off switch to ON. I will then switch individual breakers to feed certain areas of my house, during a power outage.
Electrical – What’s the current input from each leg of a portable generator into the main panel
240velectricalelectrical-panelsubpanelwiring
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Best Answer
No. You can't do that.
You have to have an interlock in the main panel.
Your idea is clever, and you think "Why not a checklist"? The answer is people got hurt doing it that way, often enough that they changed the Electrical Code to stop the carnage.
In a crisis people do not "rise to the occasion". They descend to the level of their training, and if they aren't well trained, the result is chaos. Code requires your system be built to endure through that. Simple as that.
Since your inlet equipment must be at the main house anyway (you can trench a separate cable to send it to the garage if you really want to), you can simply select commercially available inlets that include amp meters. You are interested in amp meters; there's no need to monitor voltage (plus, it's pretty easy to do with other devices such as a Kill-a-Watt).