Glossary entry (derived from question below)
Jan 13, 2007 15:37
17 yrs ago
2 viewers *
French term
United Kingdom
arrière
French to English
Tech/Engineering
Engineering (general)
puissance nominale
Hi,
I think this may be 'reverse', but help needed!
Concerning a generator:
Puissance nominale:
La puissance nominale requise est de 15 kW en monophasé 230 V, ou 15 kW triphasé 400 V avec simultanement 3 kW minimum en mono-phasé 230 V, à 50 Hz, sous cos (symbol for cos) 0,8 arrière, et dans les conditions normales d'emploi.
Many thanks!
I think this may be 'reverse', but help needed!
Concerning a generator:
Puissance nominale:
La puissance nominale requise est de 15 kW en monophasé 230 V, ou 15 kW triphasé 400 V avec simultanement 3 kW minimum en mono-phasé 230 V, à 50 Hz, sous cos (symbol for cos) 0,8 arrière, et dans les conditions normales d'emploi.
Many thanks!
Proposed translations
(English)
| 3 +4 | lagging |
Bourth (X)
|
| 4 | at a power factor [OR: p.f.] of -0.8 |
Tony M
|
Proposed translations
+4
1 hr
Selected
lagging
Medium confidence. Tony understands these things better than I.
The business about a lagging power factor being less than 1.0 makes this look especially likely. However, I have seen power factors of 0.8 many times before, with no mention of "arrière"; I suppose though that if one gives the actual factor, it is immediately obvious to those in the know whether it is leading or lagging.
See defs of leading and lagging power factor at
http://www.pge.com/docs/pdfs/biz/transmission_services/contr...
[one of those sites you can't cut and paste]
Lagging Power Factor
Lagging power factor in AC circuits (a power factor of less than 1.0) is caused by inductive loads, such as motors and transformers, which cause the current to lag behind the voltage. See Power Factor
Leading Power Factor
Leading power factor in AC circuits (0.0 to -1.0) is caused by capacitive loads or overexcited synchronous motors which cause the current to lead the voltage. See Power Factor.
http://www.cumminspower.com/na/technical/glossary/
power factor: In alternating-current power transmission and distribution, the cosine of the phase angle between the voltage and current. Note 1: When the load is inductive, e.g., an induction motor, the current lags the applied voltage, and the power factor is said to be a lagging power factor. When the load is capacitive, e.g., a synchronous motor or a capacitive network, the current leads the applied voltage, and the power factor is said to be a leading power factor. Note 2: Power factors other than unity have deleterious effects on power transmission systems, including excessive transmission losses and reduced system capacity. Power companies therefore require customers, especially those with large loads, to maintain, within specified limits, the power factors of their respective loads or be subject to additional charges.
http://www.atis.org/tg2k/_power_factor.html
You might find too that what you have is not "cos (symbol for cos)" but "cos (symbol for phi)". "Cos" = cosine and TTBOMK does not have a symbol: phi is a Greek letter and does (well, not so much a "symbol" as a letter of the Greek alphabet).
Appears "negative cos phi" is also said:
Power factor of an Inductive type circuit, in which the current lags behind the source voltage (negative cos phi) ...
www.upsonnet.com/
I imagine this is not actually negative, but less than unity as above.
--------------------------------------------------
Note added at 2 hrs (2007-01-13 17:56:28 GMT)
--------------------------------------------------
Oops! I misread some of the above/ "negative cos phi" DOES exist (I was thinking lagging PF < 1, leading PF = >1, whereas in fact the values are <1 (but greater than 0) and >-1 (but less than 0).
The business about a lagging power factor being less than 1.0 makes this look especially likely. However, I have seen power factors of 0.8 many times before, with no mention of "arrière"; I suppose though that if one gives the actual factor, it is immediately obvious to those in the know whether it is leading or lagging.
See defs of leading and lagging power factor at
http://www.pge.com/docs/pdfs/biz/transmission_services/contr...
[one of those sites you can't cut and paste]
Lagging Power Factor
Lagging power factor in AC circuits (a power factor of less than 1.0) is caused by inductive loads, such as motors and transformers, which cause the current to lag behind the voltage. See Power Factor
Leading Power Factor
Leading power factor in AC circuits (0.0 to -1.0) is caused by capacitive loads or overexcited synchronous motors which cause the current to lead the voltage. See Power Factor.
http://www.cumminspower.com/na/technical/glossary/
power factor: In alternating-current power transmission and distribution, the cosine of the phase angle between the voltage and current. Note 1: When the load is inductive, e.g., an induction motor, the current lags the applied voltage, and the power factor is said to be a lagging power factor. When the load is capacitive, e.g., a synchronous motor or a capacitive network, the current leads the applied voltage, and the power factor is said to be a leading power factor. Note 2: Power factors other than unity have deleterious effects on power transmission systems, including excessive transmission losses and reduced system capacity. Power companies therefore require customers, especially those with large loads, to maintain, within specified limits, the power factors of their respective loads or be subject to additional charges.
http://www.atis.org/tg2k/_power_factor.html
You might find too that what you have is not "cos (symbol for cos)" but "cos (symbol for phi)". "Cos" = cosine and TTBOMK does not have a symbol: phi is a Greek letter and does (well, not so much a "symbol" as a letter of the Greek alphabet).
Appears "negative cos phi" is also said:
Power factor of an Inductive type circuit, in which the current lags behind the source voltage (negative cos phi) ...
www.upsonnet.com/
I imagine this is not actually negative, but less than unity as above.
--------------------------------------------------
Note added at 2 hrs (2007-01-13 17:56:28 GMT)
--------------------------------------------------
Oops! I misread some of the above/ "negative cos phi" DOES exist (I was thinking lagging PF < 1, leading PF = >1, whereas in fact the values are <1 (but greater than 0) and >-1 (but less than 0).
Peer comment(s):
| agree |
Tony M
: Yes, 100% right, Alex! We talk about phase angle either leading or lagging (as here) — means it's either a capacitive (= leading) or an inductive load (= lagging). The cos value is always less than |1| of course, but may be + or –
1 hr
|
|
Always nice to hear from the experts, and thanks for putting me right!
|
|
| agree |
Gina W
1 hr
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| agree |
cjohnstone
1 hr
|
| agree |
Assimina Vavoula
2 hrs
|
4 KudoZ points awarded for this answer.
Comment: "Thank you to both Tony and Bourth. Your info was really helpful."
2 hrs
French term (edited):
sous cos φ 0,8 arrière
at a power factor [OR: p.f.] of -0.8
In English, we more traditionally talk of "power factor", and this is how you could express it in that case.
If you feel the need to stick to the cos φ wording, I'd suggest:
at cos φ of 0.8 lagging [OR –0.8]"
but I can't say I'm quite as confident about that way of wording it; but a little bit of internet research of similar rating specifications ought to confirm the usual formulation
--------------------------------------------------
Note added at 2 hrs (2007-01-13 18:21:02 GMT)
--------------------------------------------------
For your "sous" elsewhere, you can generally use "@" or "at":
"X volts @ frequency Z Hz", "230 V @ 16 A", etc.
If you feel the need to stick to the cos φ wording, I'd suggest:
at cos φ of 0.8 lagging [OR –0.8]"
but I can't say I'm quite as confident about that way of wording it; but a little bit of internet research of similar rating specifications ought to confirm the usual formulation
--------------------------------------------------
Note added at 2 hrs (2007-01-13 18:21:02 GMT)
--------------------------------------------------
For your "sous" elsewhere, you can generally use "@" or "at":
"X volts @ frequency Z Hz", "230 V @ 16 A", etc.
Discussion