What type of switch is best for an appliance garage? Is there a limit switch that has a 20 amp rating?
To switch the receptacle.
An appliance garage is a box with doors on a kitchen counter where people put things like toasters and food processors. The receptacle has to be off if the door isn't open.
I would want the limit switch to control a contactor in an application like that. I would be inclined to have a thermal switch in series with it too.
Joe
why does the receptacles have to be OFF? my first time hearing this.
I think I know what you are refering to this and just a suggest but a door jamb switch may work for your useage but the curpit is the rating of jamb switch IIRC it will be about either 5 or 12 amps depending on what model you get.
Merci,Marc
The OP is in Canada. It is code up here for the receptacle be off if the door is shut.
Square D has a class 9006 L100/300 series rated for 20 amp continuous (page 21-34, digest 175) but you are going to pay for it. Other manufacturers have similar but I don't have current catalogues. As far as size goes I would go for the small switch (less damage to the cabinet over time) to a relay, it may be about similar in bulk. I am glad we don't have that requirement.
I'm going to move this to the Canadian Code Section.....may get the appropriate responses there.
Square D has a class 9006 L100/300 series rated for 20 amp continuous
I thought it was a normal thing for residential work, but the wholesalers haven't heard of such a thing, and I have to do two. At the first I used a limit switch and a 20 amp relay, because the wholesalers told me a 20 amp limit switch isn't available. Now I know better and I think the switch alone is a better option.
Thanks sabrown.
First do you need a 20 amp receptacle? Not if the appliance is less than 1440 watts. Appliance garage receptacles are not counted as counter plugs.
Most limit switches are rated 10 amps or less and i think there is at least 1 door jamb switch rated at 15 amps. Trouble with these switches is they are not suitable for anything but a hinged door and usually must be installed in the hinge side to ensure the plunger is activated. We require the power to be off when the garage is even partly closed and that cannot be done with a door jamb switch.
A limit switch and small contactor in a proper enclosure is what is needed but some inspectors will let you use a relay inside a 6X6X4.
What's a proper enclosure for a relay? It was my understanding that CSA approval wasn't needed as long as the box didn't have control buttons (etc.) cut into the cover. I've seen relays, transformers, fuses, programmable controllers, contactors and time clocks put into electrical boxes. If our inspectors started enforcing this, it would start a whole new industry in Saskatchewan, a lot of it fixing my work.
I guess this is a common question and there is no simple answer but I will give the CSA speech
Any assembly of approved components is a new product. Just sticking a relay in an electrical box does not make an approved control. There might have to be a barrier if there are mixed voltages. What about the heat produced by the relay? what environment? Did you correctly allow for wiring space? Is O/C protection required?
I recognize that many inspectors and electricians look at a simple cube relay in an aluminium box or a couple of stacked 4" boxes and extension rings as not worthy of a field approval.
It is a pretty common practise but is not covered by part 2 or part 1 as an approved assembly.
The legal way is more onerous and frankly I doubt that many jurisdictions would require the field approval.
If you mix voltages like class 2 for the garage switch and stuff that in a general purpose box I better see a barrier or product approval label. 120 volt relay and a general purpose box with lots of room and I might not look closer.
Every controls manufacturer should have an enclosure for one of their contactors. that is the code compliant way but as you noted it is not a common requirement by inspectors.