Heat tape question: flexwatt

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Originally Posted by BrianWilson

Here is the video that shows them with a grounded cord.

https://www.youtube.com/watch?v=tPhnnoiWRCg

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The wire your talking about is the green ground wire, And on them racks as long as the thermostat your using in grounded your fine.

Ive touched plenty of FB racks and got shocked, the rack has to be grounded if you dont like getting shocked on occasion

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Originally Posted by RichsBallPythons

The wire your talking about is the green ground wire, And on them racks as long as the thermostat your using in grounded your fine.

Ive touched plenty of FB racks and got shocked, the rack has to be grounded if you dont like getting shocked on occasion

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They must do a really crappy job wiring their flexwatt then. I just hooked up a piece of flexwatt and went over it with my multi-meter and it was completely insulated.

You absolutely want to ground the metal shelf if you are putting the heat tape directly on the shelf! Due to the very thin insulation on heat tape you can, and likely will, get a small induced charge in the rack itself. This has nothing to do with a crappy installation but rather physics. It will not happen every time but will happen very frequently.
There is also a significant risk of a real shock. Due to the nature of our hobby- tubs sliding in and out all the time- you run a pretty decent risk of wearing through the insulation sooner or later and then you will get a real nice 120V shock when you touch the rack.
I generally recommend you use a layer of pvc sheet (1/4" works great) or 1/4" plywood on the shelf and install your heat tape on that. Besides the benefit of not having to ground your shelf you also get much better heat transfer into your tubs. If you do want to ground the shelf you will need the three prong cord. Black and white wires go to the heat tape and the green needs to be clamped to the shelf.

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Originally Posted by Reptilebasics

You absolutely want to ground the metal shelf if you are putting the heat tape directly on the shelf! Due to the very thin insulation on heat tape you can, and likely will, get a small induced charge in the rack itself. This has nothing to do with a crappy installation but rather physics. It will not happen every time but will happen very frequently.
There is also a significant risk of a real shock. Due to the nature of our hobby- tubs sliding in and out all the time- you run a pretty decent risk of wearing through the insulation sooner or later and then you will get a real nice 120V shock when you touch the rack.
I generally recommend you use a layer of pvc sheet (1/4" works great) or 1/4" plywood on the shelf and install your heat tape on that. Besides the benefit of not having to ground your shelf you also get much better heat transfer into your tubs. If you do want to ground the shelf you will need the three prong cord. Black and white wires go to the heat tape and the green needs to be clamped to the shelf.

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+1, I would still recommend grounding the rack regardless. We take many other minor precautions in this hobby that I even find silly sometimes. Why skip out on something that is potentially fatal?

Why i always recommend Ranco or Johnson for Metal racks as they are grounded. If flexwatt is wired up right youll be fine with just the thermostat. If you want to go the extra mile get the 6ft 3prong plugs, and do what was stated.

Black/white wires to be soldered to the metal strips, And green one can be Screwed to its shelf and then covered with Electrical Tape or liquid electrical tape.

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Originally Posted by RichsBallPythons

Why i always recommend Ranco or Johnson for Metal racks as they are grounded. If flexwatt is wired up right youll be fine with just the thermostat. If you want to go the extra mile get the 6ft 3prong plugs, and do what was stated.

Black/white wires to be soldered to the metal strips, And green one can be Screwed to its shelf and then covered with Electrical Tape or liquid electrical tape.

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Thermostat being grounded will only protect the wires from the thermostat back to the outlet, which is no doubt a good thing, but does nothing for the parts you are exposed to everyday.

also no reason to insulate the connection from the wire to the shelf... the ground wire doesn't even need to be insulated, you can use a bare wire if you want. All your doing is making sure any metal part that could possibly be exposed to electricity has a direct low resistance path back to ground to cause an over current and trip the breaker.

Opposed to it becoming electrified and you personally complete that path later by touching the rack, as you have already experienced. Normally the human body resistance is too high to trip a breaker so you get hit until you break the connection. If it grounded, it trips as soon as something happens and the hazard is gone.

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Originally Posted by Reptilebasics

You absolutely want to ground the metal shelf if you are putting the heat tape directly on the shelf! Due to the very thin insulation on heat tape you can, and likely will, get a small induced charge in the rack itself. This has nothing to do with a crappy installation but rather physics. It will not happen every time but will happen very frequently.
There is also a significant risk of a real shock. Due to the nature of our hobby- tubs sliding in and out all the time- you run a pretty decent risk of wearing through the insulation sooner or later and then you will get a real nice 120V shock when you touch the rack.
I generally recommend you use a layer of pvc sheet (1/4" works great) or 1/4" plywood on the shelf and install your heat tape on that. Besides the benefit of not having to ground your shelf you also get much better heat transfer into your tubs. If you do want to ground the shelf you will need the three prong cord. Black and white wires go to the heat tape and the green needs to be clamped to the shelf.

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Thank you! The voice of knowledge, entered the discussion!

Don't go getting my ego into this. Not good :)

I was looking at an NSF style metal shelf while packing some hides this morning and noticed that each metal shelf on those is insulated from the legs of the rack and other shelves by the plastic retainers they use to assemble. I am guessing these shelves get used for this application quite a bit. You need to be sure to ground each shelf due to the insulators! Overall I think the best bet is still to use some type of material as a base on the shelf so you get better heat transfer and do away with all of this grounding hassle.