ECN Forum Forums General Topics of the Trade Non-US Electrical Systems & Trades Unexplained Power Consumption

Good catch, Texas! In my experience, not too many sparkies know enough about kWh meters. I myself didn't know until I started educating myself on the topic a couple of years back.

Do the nameplates of your meters actually read "revolutions per kWh"? Ours bear the rather cryptic abbreviation "Kh" (watthours per revolution). So, your typical modern 240V single-phase residential meter is a 7.2 Kh (7.2 Wh per revolution, or 138.9 revolutions per kWh), but there are older ones out there that are 12, or 3.6. Old 120V meters (extremely rare by now) are typically 1.8 Kh. 3-phase meters can be a higher Kh (20+), and new digital ones are usually 1.

One of ours says both. Rr 138 8/9, and Kh 7.2

So that's what "register ratio" means! I was told Rr stood for "register ratio" but that I didn't have to worry about it. I never made the connection. Yes, this information is on all North American meters (that I know of), albeit in cryptic form. Canadian meters are the same as US meters. It's all one market. (Although, according to www.watthourmeters.com , Canada held on to the single-phase A-base quite awhile longer than we did. Anyone know anything about this?)

Russian meters turn up from time to time on eBay. I've seen them from the '50s to the '90s. The ones from the '50s have the nameplates all in Cyrillic characters and can be difficult for a Westerner to decipher. The ones from the '60s on have the electrical terms in international standards, so the meaning is much clearer. (Everything else is still in Cyrillic.)

These meters have rev/kWh on the dial. North American meters do not. If you know what Kh means, or Rr, you can figure it out. Otherwise, it's a mystery.

[This message has been edited by yaktx (edited 02-06-2006).]

[This message has been edited by yaktx (edited 02-06-2006).]

I have got an old Canadian Sangamo S 3 meter which has an kh ratio of 1 1/3 which equates to 750 rev. kWh.

to work out kh ratio from revs kWh

1 divided by 750 times 1000 = kh.

as classicsat says it works out the same

1 / 138 8/9 * 1000 = 7.2= kh


In New Zealand most meters are expressed in revs / kWh which is according to the British Standards.

some Dutch meters have the constant as C = 600 or 600 omw / kWh.

I have also seen the Russian meters on Ebay, interesting to note that most of the very old meters are 3 dials and only 5 Amps base load. What is mentioned already that on the nameplate the numerals are in Cyrillic, the dial has the normal numerals.

In Egypt in 1986 I saw meters with actual Arabic numerals / symbols on the dial drums as on the nameplate. Perhaps one of our Egyptian friends can sent us a picture from those meters.

Mine is 166-2/3 revs/kWh.

Silly me...I forgot another common cause of sudden jumps in electric bills....

Check all water heater elements for a fault to ground. A small crack in an element will allow a loss of electricity through the plumbing- as well as make sure the heater spends more time "on." This fault can exist for quite some time before either the element completely fails, or the breaker trips.

Pauluk


Has to be a Sangamo S 200.31 or S 200.33

20 - 80 Amps at 240 Volts 50 Hz.

Cheers Ray.

Almost!

Yes, the name plates show a U/kWh figure (Umdrehungen = revolutions).
I just had a look, our two meters are 800U/kWh and 480U/kWh. Another common figure is 75 U/kWh.

Thanks Pauluk

Didn't think of the 2 rate version of the Sangamo series. Most meters in Auckland are off the one rate tariff for single phase supplies.