Memera 2000 40 amp b mcb

[davelx]

Yes this is the thing. I worked it all out upgrading from 6 to 10mm and a 40amp type b mcb. Then someone said the mcb has 6kw max. These kilns are 7 to 7.5kw, so what would I do?

6kA NOT 6kW. 6kA is 6000 Amps - a measure of current, not power - and refers to the maximum current that the device can safely break under fault conditions, and depends amongst other things on the contact spacing and the speed of contact opening. If it attempts to break more than that then there is the danger of a sustained arc resulting in severe damage to the MCB, surroundings and possible danger to life. MCB in domestic CUs are generally rated at 6kA breaking capacity. MCBs used in commercial distribution boards are generally rated higher at 10kA.

This has nothing to do with the maximum load that can be placed on a MCB under normal operating conditions - that is simply a matter of its current rating. As has already been mentioned, a 40A MCB is suitable for loads that current up to 40A, which is nominally 9.2kW (kilowatts - a measure of power) although in reality (a) they should not be run at maximum current continuously as this may result heating that may eventually damage the MCB or adjacent devices and (b) conversely, running an MCB at up to 1.45 its rated current will not cause it to trip but should no be done intentionally for any length of time (for the reason mentioned above).

 

[mcat74]

No. It is 6kA.

Oh yes. So my proposed setup should be all ok?

 

[mcat74]

6kA NOT 6kW. 6kA is 6000 Amps - a measure of current, not power - and refers to the maximum current that the device can safely break under fault conditions, and depends amongst other things on the contact spacing and the speed of contact opening. If it attempts to break more than that then there is the danger of a sustained arc resulting in severe damage to the MCB, surroundings and possible danger to life. MCB in domestic CUs are generally rated at 6kA breaking capacity. MCBs used in commercial distribution boards are generally rated higher at 10kA.

This has nothing to do with the maximum load that can be placed on a MCB under normal operating conditions - that is simply a matter of its current rating. As has already been mentioned, a 40A MCB is suitable for loads that current up to 40A, which is nominally 9.2kW (kilowatts - a measure of power) although in reality (a) they should not be run at maximum current continuously as this may result heating that may eventually damage the MCB or adjacent devices and (b) conversely, running an MCB at up to 1.45 its rated current will not cause it to trip but should no be done intentionally for any length of time (for the reason mentioned above).

100% and thanks for clarifying. Someone mentioned I passing 6kw max but obviously meant 6ka, which won't happen. So all good many thanks for clarifying all and good to go.

 

[Risteard]

The actual voltage in your house us most likely around 240v

(Test it and see)

Which for a resistive load like a kiln will put the current up.

The actual instantaneous rms voltage will fluctuate, and is not fixed. Hence voltage tolerances.

 

[JohnD]

"Around"

 

[Risteard]

"Around"

Which could be said to be 230V +10%/-6%.

 

[JohnD]

But (in the UK) is in reality based on 240v

 

[JohnW2]

The actual instantaneous rms voltage will fluctuate, and is not fixed.

The voltage will certainly fluctuate.

However, to perhaps be a little pedantic, one cannot have an "RMS value" of an 'instantaneous' voltage' - since RMS only has meaning over a period of time.