Energy does not add up!?

[Clintonb]

I have a 3 phase supply from my electric company and i have a shed that runs off a single phase all on it's own. I have installed a series of heaters into that shed and the power rating is 550W. This is quite a large rating and i assume it to produce quite a lot of heat. The proplem i'm having is that it doesn't produce much heat at all! If i compare the 550W heater (that makes only heat) with an infra red globe which gives both heat and light, it seems like the light outputs more heat? I took an inital meter from that phase's meter and i let it run for 1 hour. The meter reading to my shock was the number of heaters X 0.550KW for that hour which is what you would expect. The problem like i said is that i'm told by the manufacturer that it should be getting much hotter and i can have my hand 0.5 cm from the element and i'm not burning nor is it producing a reasonable amount of heat given the energy it consumes.

Can anyone explain how it is physically possible to absorb the required energy but not give the required output. I have been told that i need to balance the three phases to correct the problem but if i input 240V at 2.5 amps and i draw 550W every hour then surely i should get the required heat irrespective of wether it is balanced or not? Can anyone explain where i might be losing out?

Regards
Clinton

 

[Pat Tester]

What sort of heaters are you using ?

 

[pushrod]

The only thing i would say about your little comparison test is that many infra red bulbs are 250 watt and directional so it is not surprising that they feel hotter than the heater which is probably dissipating its energy over a much larger area and so felt cooler.

 

[Des 56]

Following on from Pat tester

Different heaters have different types of radiated heat .warm air convected,infra red

A typical quartz halogen will not heat the air around it,rather it radiates heat onto the object it meets
You may be comparing a room heater and thie quartz type perhaps and not gauging the percieved heat effects to the type of heater used

 

[Clintonb]

The comparison should be exactly the same for both heaters. Both heaters emit heat as infra red and both are directional. The heaters i am referring to is basically an element that produces the heat and it is in the center of a satelite dish structure the pushes all the energy straight down the same way that the infra red directions the heat. The only difference is that the heater i am using has a ceramic element unlike the light bulb.

 

[pushrod]

Would be helpful if you could actually name your heaters so people could check the specification of them. Heaters are normally purely resistive and have no effect on phase difference between current and voltage are yours a bit unusual? If somehow they are producing a phase difference then it could be that you are comparing volt amps with watts which could give you the difference.

Regarding the 3 phases, i think if your loads are unbalanced this is costing you unnecessary money but i don't think it is responsible for the problem you are describing - i am certainly no expert on this mind.

 

[Rufuxinix]

I have a 3 phase supply from my electric company and i have a shed that runs off a single phase all on it's own. I have installed a series of heaters into that shed and the power rating is 550W. This is quite a large rating and i assume it to produce quite a lot of heat. The proplem i'm having is that it doesn't produce much heat at all! If i compare the 550W heater (that makes only heat) with an infra red globe which gives both heat and light, it seems like the light outputs more heat? I took an inital meter from that phase's meter and i let it run for 1 hour. The meter reading to my shock was the number of heaters X 0.550KW for that hour which is what you would expect. The problem like i said is that i'm told by the manufacturer that it should be getting much hotter and i can have my hand 0.5 cm from the element and i'm not burning nor is it producing a reasonable amount of heat given the energy it consumes.

Regards
Clinton

The easiest would be to move the heaters somewhere else (another phase) and see what the result is.