MemberJanuary 28, 2018 at 12:00 am
Our Vol. Fire Dept. is relocating to a station which only has 1 phase power. We’d like to keep this griddle.
MemberJanuary 28, 2018 at 11:33 am
Yes it is easily done. Attached is the service parts manual with the single phase conversion wiring diagram.
You will need a #6/3 SO orSJO cord and have to punch out for the larger cord strain relief and a 40 amp plug and socket. Make sure all connections are CLEAN and bright and tight.
MemberJanuary 28, 2018 at 5:04 pm
Looks like the numbers you gave are for a 24″ griddle, which only has two elements. Their 536TG is 36″ wide and has THREE elements. A 40 amp plug and receptacle would be under-rated for that 36″ grill.
Star uses the same element for 208 and 240v. My calculations came up with 4.8 ohms total resistance of all three elements (in parallel). So, that griddle will pull slightly more than 43 amps @ 208v, or 50 amps @ 240v.
Yes, converting the unit to single phase is simple enough, since that’s just a matter of wiring it for single-phase inside the unit’s junction box. I recommend using split-bolts for that instead of wire nuts. There doesn’t appear to be an input terminal block in that grill.
I suggest that the electrical supply service to it done by a licensed electrician, who can determine what options they have for that size of a circuit (50a minimum for 208v service, or beefing it up to 60a for 240v).
MemberJanuary 28, 2018 at 6:49 pm
I went about it the other route. 3 heaters should be 12,000 watts. at 240 volts that would be 35.29 amps. The big problem I see is that junction box isn’t big enough for split bolts. And what I don’t know is if it is big enough to knock out the hole for the cord retainer and still have clearance for the nut.
He will also have to put 7 to Y and 8 to Z. It’s just a 2 by 4 standard knock out box with 3/4 knock outs. I certain one could replace it with a 4 X 4 deep with 1″ knock outs. for the extra room.
MemberJanuary 28, 2018 at 10:35 pm
Let’s see if I can do this after MUCH beer and a glass of wine.
Here’s the basic power formula:
P is watts
V is volts
I is amps
So 12,000w ÷ 240v = 50a
Here’s for resistance:
So 240v ÷ 50a = 4.8Ω
I don’t know what other route you used.
Funny that I just stumbled on this calculator while looking for those images:
MemberJanuary 29, 2018 at 8:30 am
I must have plugged it into the calculator wrong or something. When I redo it it is 50. Alternately one can multipy the three phase rated current by 1.73 for a true value. Posted on the drawing as 28.9 amps at 240.
Found a more resent drawing spec for the star griddles by looking at the heater part number and where it is used. Seems the only one they forgot to update was the TG I’ve gone through all models and each has the same spec and wiring as well as heater number. Just drawn different and easier to read.here.
It can still be done with STO or STOW with 6 wire, (NEC 400.5), (55 amps 2 carrying conductors) but if it can be hard wired with liquidtite conduit and MTW one can use 8 wire. Big difference in the connection box as that can be done with 3/4 conduit instead of having to change the box for connection room.
Log in to reply.