panel meters

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socalelect

Member
Location
so. cal
i am in need of a full panel meter compliment for a generator in need of voltage , amps or watts , and freq i havent had any luck finding these even at grainger , i can find the voltage but not the amps or watts with the current xformers and such

any help is mucho appreciated
 

jdsmith

Senior Member
Location
Ohio
For a generator you should use switchboard class meters - the Yokogawa recommended above is an excellent choice - I have installed many Yokogawa meters as well as Crompton. If you choose to install an electronic energy or power quality meter you should still install the analog meters as well - with analog devices you can see all of the quantities at one time and see deflection and transients much better in real time than with digital devices.

Both Crompton and Yokogawa meters are available from full line electrical distributors.

A power quality meter with waveform capturing capability and adjustable triggers is a great fit for a generator. Some of the fancier power quality meters have excellent transient recording capabilities based on programmable setpoints as well as longer term load profile type recording.
 

iceworm

Curmudgeon still using printed IEEE Color Books
Location
North of the 65 parallel
Occupation
EE (Field - as little design as possible)
i am in need of a full panel meter compliment for a generator in need of voltage , amps or watts , and freq i havent had any luck finding these even at grainger , i can find the voltage but not the amps or watts with the current xformers and such

As sue asked:
What size generator is this for?
Additionally, 3ph?
What voltage? Do you need PTs?

For larger generation (>500kw), the protective relays already supply half (or more) of the metering circuits, and the costs of downtime are generally killers, so one tends to spec meter quality such as templdl and jdsmith suggested. But if you are equiping a 20kw - 100kw, and downtime is inconvenient, but not horribly costly, the budget could easily be a limiting factor.

Taking a hint from you are looking at Grainger, try Newark, Allied, Mouser, digikey. They should have package CT and meters.

Watt meters are going to be a bit more difficult. If the appliction is single phase .... okay, to many variables. Need some more data.

One other issue. If you are looking to mount analog panel meters to a panel fixed to a small generator frame, They have a habit of shaking themselves to needle-sticking art objects - often rather quickly.

(edit - added thought)
I bought an ammeter (and CT) and a freq meter for an off-grid house gen a few years ago from the local commercial small gen store. Not a seller of the Generac stuff - rather, this guy had Listers and the like, packages as well as bare gensets. He had basic instruments, volt, amp, cts, freq in his counter- didn't have pf or kw for single phase.

ice
 
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socalelect

Member
Location
so. cal
iceworm

the generator is a 15 kva single phase, it gets used often and they seem to always over load one leg of it, and its a pain to go out with the amp clamp and get it close to being " balanced"
i was thinking for volts 0-150 , amps 0 to 75 and a freq 55 to 75 hz so 60 will land right in the middle i plan on installing the volt and amp for both legs and one freq meter

the only catch is the budget for this is 300 or less in parts
 

iceworm

Curmudgeon still using printed IEEE Color Books
Location
North of the 65 parallel
Occupation
EE (Field - as little design as possible)
iceworm

the generator is a 15 kva single phase, it gets used often and they seem to always over load one leg of it, and its a pain to go out with the amp clamp and get it close to being " balanced"
i was thinking for volts 0-150 , amps 0 to 75 and a freq 55 to 75 hz so 60 will land right in the middle i plan on installing the volt and amp for both legs and one freq meter

the only catch is the budget for this is 300 or less in parts

Hummm ...
Two CTs, an A/B/Off switch (shorting type so you don't open the CTs - or two CTs and two meters), volt meter, volt meter sw, freq meter, panel, panel support (shock mounted if it in on the gen skid), Nema 3 or better if outside - and $300 material, labor extra.

Engineeringly speaking (using exact definitions) - you're hosed.

How about considering a Nema 12, hinged cover, J-box, mounted on/near the gen, with conductor loops for a clamp-on and terminals for voltage measurements? Any of several of the newer DVMs will read frequency - probably already have one. That would make it a lot easier to do the measurements - and keep the costs down. Should be well below budget.

(edit to add) Arrggg new thought -
There have been several post about Kill-A-Watt type devices that sound like they might do what you need and be in budget. I can't tell you about them - but Gar could.

ice
 
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socalelect

Member
Location
so. cal
ptonsparky this has nothing to do with my personal budget. this is what my employer has alotted me for this project

i rarely get projects with a "blank check" things would be much eaiser if i did
 

templdl

Senior Member
Location
Wisconsin
Typical employer.
He probably doesn't have a clue as to what it costs in order to provide the metering as appears to be required.
Maybe some radio shack meters would make him happy if they have them. But I would present the boss some options and let him make the decission on the quality vs the cost..
 

socalelect

Member
Location
so. cal
temp, you hit the nail dead on . on most things they have zero clue about cost , no clue about how much copper has gone up so i get stuck with alum. and they wonder why i have a special barrel in the shop for scrap copper
 
Location
NE (9.06 miles @5.9 Degrees from Winged Horses)
Occupation
EC - retired
Unless someone is messing with the gen set most likely the hz will be stable. Scrap that meter. Unless you overload the hell out of it the voltage will be good, scrap that one. A CT and a panel mount meter will run you about $150 per set. Not counting shipping and a box to put them or your labor. AD offers some current monitors that can turn on a light if your employer can be happy with some sort of warning. Put one on each leg, wire it into a pilot light. They are about $75 each plus S&H. As stated earlier give him some options. Give the cost of what you would like to do, then show him what you can do for less than his $300.
 
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