Reducing Power to protect an element - how?

[aamcle]

I'm in the UK so I have a 240v supply at 13 Amps.

I need help with a 40 litre 8 - 9 US gallon Buffalo manual fill water boiler (tea urn) that I use as a kettle and part of a Kettle Rims.

The original 3kw element was the concealed type flush with the base of the urn, it burnt out a common failure in the model of boiler. I then fitted a 3KW LWD element and got on with brewing however using this new element requires that I leave 7 - 10 litres of water in the boiler just to keep it covered.

I've rebuilt my brewery https://www.homebrewtalk.com/showthread.php?t=629570 and I'd like to reduce the amount of water I need to leave in the kettle and I have been offered the chance to buy a replacement original Buffalo element BUT I know they are fragile.

If I use the LDW element for bulk heating getting to strike temperature/the boil and the replacement element only during recirculation to maintain temperature then I could use the replacement Buffalo element at a reduced power 1.5 - 2kw and I hope protect it from failure.

First question is would reducing the power protect the element?

If my idea would work what is the best way to do it?

I'll be using a PID to monitor and control the mash temperature so I want a way of reducing the power of the element that will be compatible with the PID.

Many Thanks. aamcle

 

[processhead]

First, It would be important to know what is the failure mode of the Buffalo element. If the element is failing because the outer insulated sheath is failing, general corrosion, or bad connections, then just reducing power probably will not protect it.
You may not be able to determine that until you get the old element out of the kettle.

If the original element fails because of overheating, then reducing the maximum power to it may prolong its life.

A fairly easy way to limit the power to an element is to use a SSV. This can be used in conjunction with other temperature control devices to limit full power from being applied continuously to the element.

 

[aamcle]

Err.. I'm not sure if this helps but the bottom fell off it. ridge section that the actual heater wires run in broke and a section fell off.

aamcle

 

[processhead]

From your description, I doubt that reducing power will do much to prolong the life of the replacement element.

 

[aamcle]

that's disappointing.

Thanks. aamcle

 

[augiedoggy]

Do you really think the replacement will fall apart the same way?

 

[aamcle]

As it will only run to maintain the mash temperature I hope not but confident that's another matter.

aamcle

 

[kydan47]

My PID has a setting outL & outH which allows me to dial in my boil. I set mine to 60% outL & outH at 70% which on 3500 elements is 2100 & 2450

 

[BBBF]

My PID has a setting outL & outH which allows me to dial in my boil. I set mine to 60% outL & outH at 70% which on 3500 elements is 2100 & 2450

You still have a 3500w element. It's just has electricity flowing through it 60% of the time instead of 100% of the time.