I want to connect a single phase 24 amp kiln under my waterproved pergola. What electrical work needs to be done and how much would it cost approxmatly?
That kiln requires a 30 amp circuit, minimum. 24 amps x 125%= 30 amps per National Electric Code (NEC).
Without more info, I'll need to make a few assumptions. For the sake of estimating the cost I'll present the following scenario:
1...The distance from your electric panel to the pergola is approximately 100 feet.
2...The circuit will be underground. I'll assume that you will be able to hire someone to dig an 18 inch deep trench from the electric panel to the pergoda for $10 hr. While this should only take 3 or 4 hrs, depending on soil conditions, it could take all day. So I'll assume $80 for this.
3...This will be a 240 volt, 30 amp circuit (see why below).
4...Since you posted under the Intermatic T171, and since that is a 120 volt timer, that the kiln is 120 volts.
5...Unless the pergoda is fully enclosed, NEC still requires a weatherproof installation.
For starters, I don't recommend a 120 volt kiln. Most people I've known who had a kiln always seemed to want a bigger one ;-) Again, I'll do the estimate for a 240 volt, 30 amp kiln, as the price difference compared to a 120 volt circuit is about the same.
Also, I strongly recommend using 3/4 inch PVC conduit as opposed to 1/2 inch PVC or UF (direct burial) cable. 3/4 inch conduit doesn't cost much more than 1/2 conduit and will allow you to install wire up to #6. UF cable, in my opinion, is out of the question because if you ever decide that you want a larger kiln the direct buried UF cable is _not_ easily replaceable. A conduit and wire installation is about the same price as UF anyway.
Here's the breakdown (US dollars):
$ 10 - 30 amp, 2-pole circuit breaker
120 - 300 feet of #10 THWN COPPER wire (40 cents a foot)
20 - 1 bundle (100 feet) 3/4 inch PVC conduit
10 - 3/4 inch PVC elbows, fittings, straps
20 - Weatherproof box and weatherproof cover
+15 - 30 amp receptacle
+100 - 2 hrs labor @ $50 hr. (possibly 3 hrs.)
+80 - labor for trench
+140 - Intermatic T172R (weatherproof) 240 volt timer
Other considerations are that, if indeed, the circuit is 100 feet, you should consider using a #8 THWN COPPER wire to account for voltage drop (add $60, @ 60 cents a foot) Using a #10 wire at that distance may not allow the kiln to get to the desired temperature.
If you are anticipating things like lights, 120 volt receptacles, fans and such, the best way to do all that is to install a subpanel at the pergoda.
That should get you in the ball park as far as price. Of course, you can make adjustments accordingly. Remember that prices can vary greatly depending upon geographic location. Also, if you call a contractor for an estimate, _after_ they give you the price, _then_ ask how much they will knock off if you dig the trench.
A contractor price of $600 would not be unreasonable.
Hope this helps.
Jun 02, 2010 |
Electric Intermatic T171 24 HOURS 40 AMPS...