Furnace Energy Consumption

When the furnace shuts down, does some alternate energy source kick in on the auxiliary transformer?

Er... you do mean mega-volt-amperes ? This is generally written as MVA, as opposed to millivoltamperes, which is written as mVA ... just to be sure.

Its MVA sir

i hope you were not offended by my editorial correction, just pre-empting some other caustic poster

Btw, what kind of a furnace? Induction by any chance ? Are there lots of capacitors on the system ?

It is a submerged arc furnace of 10 MVA .Unfotunately there is no capacitor bank connected either in furnace transformer or in the system.The plant is in kuwait.

Anyway, you have clearly mentioned kWH, so any capacitors wouldn't have any effect on that.

Sorry, not my field. Anyhow, given that it is Kuwait, the supplier must be falling over himself to help ? Any negative feedback, and he is a goner.....right?

OK I've only worked on furnaces up to 3MW. The secondary control was off a separate 11KV fed transformer.

Take the control off a separate supply.

You write "auxiliary energy consumption".....

1. Do you mean the reading of a Watt-hour meter (kW-h)?? - that is energy consumption.
2. If the furnace is off for longer time than it is on, then a smaller load for the longer time could build up a greater change in kWh recorded.
3. How big an auxiliary energy consumption are you seeing? Furnace running and furnace stopped values please.
   

yes sir I mean KWh ie energy consumption.The auxiliary energy consumption is greater (more or less 2000 KWh ) when the furnace is off than that in on.