This is different

[JTW37]

I picked up a contactor from a guy I am acquainted with. He owns the company that makes these. It is a Mercury switch. He said it will never wear out. Wanted me to try it in my next oven build. My wife helps make these.

My second oven is almost complete and I can't wait to try this one out on it.

[baz]

Originally Posted by JTW37

I picked up a contactor from a guy I am acquainted with. He owns the company that makes these. It is a Mercury switch. He said it will never wear out. Wanted me to try it in my next oven build. My wife helps make these.

My second oven is almost complete and I can't wait to try this one out on it.

i have not tried one but heard that they were like heavy duty stuff

[FigureLLC]

i'm familiar with mercury switches, but only in tilt applications (i.e. off when level, on when tilted 15deg). how does this type work?

[JTW37]

Okay, talked to one of the Bosses that make these, so here's the best I can tell you on it's operation.

there are two of the contact cylinders put together to do what we need for ovens. Like I said earlier, my Wife makes items for it. She finishes up electric coils that are incorporated into each cylinder. These coils are energized to make the mercury contact work. In the middle of the coil is a hollow cylinder, into which to mercury is placed and then there is a metal rod, that is placed in a glass type of Washer (for the lack of a better word) and this is placed into the metal cylinder and welded shut. Then the coils are placed into a metal covering into which the hollow cylinder is placed. Then the 240v terminals are added and the whole thing is coated with an Epoxy and baked. Then they place however many they need together (up to five I think) and then the terminals are connected with the bands you see.

Now that that is out of the way, what happens is, the current that is put to them energizes and forces the mercury to the far end and completes the circuit. It's like trying to stick two like magnets together, that pushes the mercury. With the rod still in the mercury, it makes a connection and WHA-LA, you got power. Pretty simple if you know how it works. The only thing that would ever go wrong with these are the coils. The same contactor is used in Pizza Hut ovens.

If you want anymore info on these let me know. I am finding out what the cost is for a double like mine. If interested.

[PhredAre]

Take a look at page 878 in the McMaster catalog, quite sure that these are as you have described. Have seen them in industrial applications, last forever, but the feds regulate the mercury as a bad thing for what thats worth. Do you suppose a guy could take a Ford Mustang, strip out the combustibles, patch up the glass areas, insulate it and make a powder coating oven out of it. Maybe a van would be better, just a thought. Fred

[JTW37]

How's that saying go? They are the same, but different. The must work the same as the one I have. Just never seen them anywhere but where my wife works.

[GeneNewcomb]

I've seen very few contactors wear out, none actually. Is there any other advantage to the mercury switch?

[PhredAre]

Just thinking about the Mecury switch and was wondering about the control circuit. What is the the control circuit operating voltage and current draw? Will the PID, if thats what you are using, support this contactor. Thats the thing about an SSR that makes it ideal is its low current draw on the control circuit which is conpatible with most PIDs. No moving parts in a SSR, just switchable diodes I believe. Fred

[JTW37]

Here's a bit of info:

# Ratings up to 100 AMP.
# 1 through 4 pole configurations.
# The best relay for heater loads.
# Coil voltages up to 600 volts.
# Hermetically sealed contacts.
# Suitable for resistive, capacitive and inductive loads.
# Various size and AMP rated Tilt Switches
# Solid State Relays up to 70 AMP

But I guess the best way to get your answers is to go to the Horses mouth.

www.mdius.com

[ed_denu]

Originally Posted by PhredAre

Just thinking about the Mecury switch and was wondering about the control circuit. What is the the control circuit operating voltage and current draw? Will the PID, if thats what you are using, support this contactor. Thats the thing about an SSR that makes it ideal is its low current draw on the control circuit which is conpatible with most PIDs. No moving parts in a SSR, just switchable diodes I believe. Fred

Good questions Fred. If you look up the coil data on the web site it appears that they sell various models with both ac and dc input voltages. So it appears that as long as you select a relay that is compatible with the controller you would be ok. It's interesting that the warranty is only 1 year!