Dryer Plug

[GoldDigger]

The tubular type heating elements are much more common in water heaters and cooking appliances. Naturally they cost more, so less likely to be used in dryers where the tube is not needed.

 

[Dennis Alwon]

The tubular type heating elements are much more common in water heaters and cooking appliances. Naturally they cost more, so less likely to be used in dryers where the tube is not needed.

If they did use those elements they would burn out as they need to be immersed in water

 

[don_resqcapt19]

If they did use those elements they would burn out as they need to be immersed in water

That is based on the design the elements...stoves and ovens use those types of elements and they don't need to be in water.

I think they are called "calrod" or something like that.

 

[iwire]

That is based on the design the elements...stoves and ovens use those types of elements and they don't need to be in water.

I think they are called "calrod" or something like that.

It seems those elements are used when you cannot have exposed live parts.

 

[Dennis Alwon]

That is based on the design the elements...stoves and ovens use those types of elements and they don't need to be in water.

I think they are called "calrod" or something like that.

Yes but I was talking about the water heater element that Golddigger mentioned-- I should have clarified but I thought it was obvious the range element did not have to be in water

 

[kwired]

If they did use those elements they would burn out as they need to be immersed in water

They need something to sink heat into or they will get too hot, but the type Bob posted a picture of kind of does as well - it just so happens that it is typically just air flow that the heat is transferred to. Remove airflow and any high limit controls and they will burn out as well.

The main difference with a water heater element is there is no direct acting high limit control - there must be water surrounding the element or it will not last for long. On top of that water heater elements are high density wattage - you have even more heat in a smaller area of element then you do in say an oven or cooktop element, so it needs better thermal transfer media in intimate contact with the element to pull heat away at a faster rate.

 

[kwired]

I have not tried this and am not sure, but if the element is rated at 240V and one end shorts to frame doesn't it mean that it will only see 120V across it. And will you have current flow across a 240V rated element that has 120V to it?

I guess I misunderstood what you said back here to some extent - you did say if "one end shorts to frame". Assuming that end became disconnected from it's ungrounded supply conductor and the other end was connected to a 120 volt ungrounded conductor then yes you would only have 120 volts across a 240 volt rated heating element.

As far as how can you ever short any load to ground at some point between the terminations - things happen - especially when there is physical damage involved:happyyes:

 

[Ponchik]

I guess I misunderstood what you said back here to some extent - you did say if "one end shorts to frame". Assuming that end became disconnected from it's ungrounded supply conductor and the other end was connected to a 120 volt ungrounded conductor then yes you would only have 120 volts across a 240 volt rated heating element.

As far as how can you ever short any load to ground at some point between the terminations - things happen - especially when there is physical damage involved:happyyes:

Yes thanks. that is what I meant.

In that case will there be current flow?
I don't know but probably no current flow, and if not then how will this shorted lead to the frame cause an excessive current flow? :?

 

[kwired]

Yes thanks. that is what I meant.

In that case will there be current flow?
I don't know but probably no current flow, and if not then how will this shorted lead to the frame cause an excessive current flow? :?

Apply 120 volts to a 240 volt rated resistance and you get 1/2 the rated current - but only 1/4 the watts output. If voltage is applied to a closed circuit, current will flow in proportion to the applied voltage and resistance, that law does not change.

 

[Frank DuVal]

AH, but if you look at the element, it can short by drooping anywhere along the element. Yes, the standoffs should prevent this, but for discussion, you have 240 across the whole element. If it droops halfway around the element, there will be no change, as that is the center point of the 240 v service anyway. But, if the element touches ground say 1/4 of the way along its length, then 120 is now across only 1/4 of the original resistance, or 1/2 of the original resistance seen at 120 volts, so high current will be drawn on one leg.

Most overheating situations of the element can be traced to lint partially clogging the output pipe, therefore low air flow. Less air=higher operating temperature of the element.

Frank DuVal