I bought a timer for the block heater the other day and came to find that it doesnt have the 3rd connection for the ground. Does the block heater need to be grounded using all 3 wires or can I just use an adapter so I can hook up a 3 prong extension cord to the timer?

 

A pair of pliers and a few seconds fix up any ground plug out there. Many years ago these grounded plugs meant something but for decades now the building codes all mandate that your electrical panel be grounded and this kind of makes these grounded plugs wasted effort. But they are still required for commercial use. This is why you still see them on everything.

 

Ok Awesome I just didnt know if it would make electrolasis in the cooling system or something.

 

If it touches something that creates a short it's just gonna throw the breaker switch and if something fouls in their that would overload anything it just feeds right through the ground on your breaker box. In the old days that third arm on the plug would have just been connected to a wire that atached to the electric receptacle box. In the very new or remodeled homes you may actually have a three wire system that goes all the way to the breaker box and then the wires for the third leg would be connected to the ground there.

But in any case, no juice travels through the third leg so it's not gonna affect the amount of juice that is flowing through the heater in any way. I always just break em off of anythig that I know I won't be returning to the store for some reason.

 

Current leakage from immersion heaters happens frequently, truck, dishwasher, hot water heater or otherwise, and and it doesn't trip a breaker unless the short is severe enough to overload the breaker rating. The ground return picks up this recirculating current and returns it to the source, aka either the neutral/ground buss in the breaker box if terminated there together, or out at the transformer servicing the building. In any case, bypassing this ground return leaves nowhere for the current to go except circulate through the vehicles negative neutral system aka the "ground". This can be quite devastating on ECM's not to mention set up a nasty galvanic situation. The ground lug is still a safety feature that shouldn't be ignored especially in an environment mixed with AC and DC, as well as liquids. Take it for what it's worth, but there are timers that incorporate the ground circuit. Or you can splice around the timer with a ground circuit, connecting the two cords ground conductors outside the timer.

Chris

 

Great answer Chris. And I would defintely agree.

Monster Truck...what kind of timer did you buy? You should have the Heavy Duty type that is meant for outdoor use (even if you have it plugged into the garage or somewhere inside). It should be something like this:

 

I didnt think people did that anymore

 

Like Chgris above pointed out the the ground is a safety measure for bleeding current from a bad heater element. If the ground was missing I bet you going to get a shock everytime you touched your truck on a wet day... (Trust me I learned the hard way!)

 

and if you are wet, it could be a damned good shock

 

My FIL used to have a Lance camper and he had the camper plugged in one day at the house doing some maintenance which also had the driveway soaked. I walked up in my worn out cowboy boots and leaned on the side of the camper. Found out really quick that he had a ground issue.