Generator monitoring / watt meters etc

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Old 07-26-20, 07:36 AM
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Generator monitoring / watt meters etc

I got my generator inlet, backfeed breaker, and interlock all set up. Now what is missing is a way to monitor my loads.

I came across this meter from Nooutage.com and some other very similar ones from amazon. The gist is a current transformer (donut) goes over the wire to measure current. The power comes from a small gauge wire with a fuse that taps into the feed from the generator
NPZ022 Generator Meter Kit - for single phase to 22kW

I can't see where it would be acceptable to splice on a thinner gauge wire (even with a small fuse) to the 30 amp #10 feed from the generator in the panel.
 
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Old 07-26-20, 09:44 AM
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Literature doesn't state what the displayed current is based on since there must be 2 sensors when the gen output is driving both 240 vac and 120 vac loads. In order to balance the 120 vac loads on L1 vs L2, one needs to read each current separately with 240 vac loads turned off. A clamp-on multimeter having AC volts and AC amps selection, as a minimum, for $30-$50 would be my choice. Add the 2 currents and multiply by voltage to get power. I would purchase a Kill-a-watt meter, $20, for measuring frequency. These measuring devices are portable and can be used anywhere. Once the line balance is done on a breaker panel, nothing is going to change without you knowing about the change so constant monitoring isn't necessary.
 
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Old 07-26-20, 10:55 AM
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My plan was to monitor the two 120 legs separately with two meters. My only 220 is the central AC and air compressor. Neither of which I really plan to run on generator.

My concern is mostly with how to make those connections safely for a permanent setup. I have a killawatt and fluke clamp meter. Just like the idea of seeing at a glance, what load is on the generator.
 
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Old 07-26-20, 11:07 AM
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That is a effective tester..... especially at $100.

I can't see where it would be acceptable to splice on a thinner gauge wire (even with a small fuse) to the 30 amp #10 feed from the generator in the panel.
That's how it's done. The small fuses protect the smaller wiring. This method is used daily in commercial applications.
 
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Old 07-26-20, 05:27 PM
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pjmax,

Fair enough. No issues with pigtailing a fuse holder onto the #10 I have feeding the breaker?

I'm actually contemplating mounting a work box or junction box near the panel to install this. That way my tail and wiring isn't even in the main panel.
 
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Old 07-26-20, 06:48 PM
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I install Emon Dmons. They are kwh meters that log power usage for billing purposes.
I install a 5A fuseholder and fuse on each power lead and the fuseholder is connected directly into the breaker.
 
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Old 07-27-20, 08:48 AM
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Sounds good. I actually came across these that I think I'm going to use. They fit in a decora faceplace with minor trimming. I'm going to run two, one to monitor each leg from the genny. Volts, watts, and amps at a glance. Pretty decent reviews too for the price.

Do you use any specific fuse holder, or just any holder and fuse rated for the voltage?

https://www.amazon.com/DROK-80-300V-.../dp/B01MRZAFAF
 
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Old 07-27-20, 08:41 PM
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I use good quality fuseholders as I can't have them failing or coming apart in a commercial situation.
I left a link to the type. Yes.... it must be rated for at least 240vac.
Bussman fuseholders
 
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Old 07-28-20, 11:39 AM
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Got it. Picked up a couple with nice heavy leads on them too and a pack of 1a 250v fuses.

Now just to figure our how to mount these. I'm thinking a 4x4x2 NM junction box and cut the lid to snap them in. Drill holes and use the push in bushings to hold my NM wire.
 
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Old 08-01-20, 04:23 PM
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So ended up using a 4x4x4 plastic box. Turned out half decent. Got some decent fuse holders and half amp fuses to run the meters. Each one monitors a leg from my genny.



 
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Old 08-01-20, 05:01 PM
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Very nice job.
Now the idea is to keep both amp meters reading as close as possible.
Remember..... practice safe load balancing.
 
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Old 08-11-20, 11:35 AM
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I'm going to set up an interlock. This looks pretty cool, but what is the point of this? To balance the amperage on the two hot lines from generator? Is that important?
 
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Old 08-21-20, 04:52 AM
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Pretty much. Just to see what your load is, how balanced it is, etc as you start turning on breakers. Also there's the geek factor.
 
 

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