Watch those block heater cords!

[SparkandFire]

I mostly just wanted to run the block heater because my antifreeze concentration is questionable at the moment. I blew the radiator the other day, so I only have about 1-2 gallons antifreeze and the rest is distilled water.

i did find some fleetcharge yesterday, so this weekend I am going to do a flush and get my antifreeze level to where it needs to be. unless I get rained out!

 

[84IDI-BERTHA]

Just had to add in my fun little story. happened last night, decided to plug the truck in with 15* temps at night, plugged the block heater in and BAM...nothing. wiggle the cord a little and the fireworks began. ran into the garage to unplug the cord. a quick assessment showed the previous owner did a slap job splicing the cords and left them exposed. a half butt tape job seemed to suffice. needless to say i nearly filled my pants, and lost a little hand hair. definintely check those wires, one was completely disconnected from the plug end, which was connected a few days ago when i plugged it in. scary stuff!

 

[typ4]

yeah, that would trip the breaker for THAT circuit, NOT the main. Unless the whole hose is on one breaker

its an apartment, lighting and plugs are likely on a 40 amp sub breaker for 110 circuits, running at thelimit itl blow the main, also could be a gfci main which would go first.

**** Brad I thought you knew everything

 

[travelinman31]

Finally something I can speak a little knowledgable on as I'm a Master Electrician. If it's a dead short to ground (such as a ground fault) it can and will trip a much larger main breaker before it trips the branch circuit breaker. I have seen on multipile occasions a 1200 amp main trip before a 20 amp branch circuit breaker, leaving a school completely dark all because of a bad ballast or device plugged in. Of course that large of a breaker has adjustments that can be made to increase the fault at which it will trip, whereas your run of the mill 20 amp circuit is internally fixed to trip at a certain level of fault (sometimes to high in my opinion since I've been on the wrong end of a few ground faults and NO breaker tripped Type4 is correct about the main being close to or maxed out, that little extra arc sends it over the edge before the smaller breaker will trip.

 

[redmondjp]

I read somewhere that its best not to use an Xcord above 50ft long for the block heater, it is 1500 watts and draws 15 amps or so. The longer the Xcord the more amps are being drawn, and if you have 150ft of cord on a 20amp GFCI, or breaker, you are going to trip said breaker, or GFCI. This increasing amperage can be negated by using a higher gauge cord AFAIK

This is incorrect information when talking about a purely resistive load such as a block heater. It is more or less correct when talking about an inductive load, such as a motor.

You can put a 500' extension cord on your block heater if you want to. The longer the cord (assuming that the wire size is the same for purposes of this discussion), the more voltage drop you will have across the cord. The end result is your 1500W heater may only be a 1400W one with the voltage available to it at the end of the cord. No big deal, and adding length to your cord will actually help it to NOT blow the circuit breaker by reducing the total load on the circuit.

(I'm an EE with 25 years in the power business, BTW)

 

[OLDBULL8]

It's the LAW, OHM's that is. Go figure.

V= Volts
I= Current (Amperage)
R= Resistance
W= Watts