I posted originally on April 30th, but have edited the post with updated information:
I need advice for sizing some transformers. I have a test kitchen that has two cooking sections in the same room. One section will have (4) 208v / 3Ph 17KW electric fryers. The second section has (3) of the same fryers and (2) 208 / 1 Ph / 2700 watt sandwich grilles and (1) 9KW / 3Ph griddle. In addition to this is a walk-in freezer at 12KW (208v / 1Ph) and a 50 gallon water heater (3500 w / 1Ph) (standard residential)
This is the set up: Each "section" as I call it is actually a portable wall with a vent hood, suppression system, and the electrical outlets for the above listed appliances already installed. On the other side of this wall is a 225 amp MLO / 3 Ph Square D QO panel. All I am required to do is feed the panels, plus the branch circuits for the freezer, exhaust fan and water heater.
The MDP is 480V.
Based on table 220.56 I have calculated the following:
Fryers 7 x 17KW = 119,000
Griddle 1 x 9KW = 9,000
Sandwich grill 2 x 2.7KW = 5,400
Freezer 1 x 12KW = 12,000
Water Heater 1 x 4.5KW = 4,500
Exhaust Fan 1 x 1.5KW = 1,500
Total 151,400 x 65% (6+ appliances) = 98,410
98,400/ (208 x 1.732) = 273 A
Based off of my calculations it seems a 112.5 KVA transformer would be sufficient. Am I missing something, or have I calculated incorrectly? It just seems as though all of these appliances should require a larger transformer. Also, I realize that based on 220.56 I can use a 65% demand factor, but I know that these units will all be coming on at once and I would assume the fryers will cycle at similar rates. I just don't want to under size the transformer.
Thank you in advance for your help.
I need advice for sizing some transformers. I have a test kitchen that has two cooking sections in the same room. One section will have (4) 208v / 3Ph 17KW electric fryers. The second section has (3) of the same fryers and (2) 208 / 1 Ph / 2700 watt sandwich grilles and (1) 9KW / 3Ph griddle. In addition to this is a walk-in freezer at 12KW (208v / 1Ph) and a 50 gallon water heater (3500 w / 1Ph) (standard residential)
This is the set up: Each "section" as I call it is actually a portable wall with a vent hood, suppression system, and the electrical outlets for the above listed appliances already installed. On the other side of this wall is a 225 amp MLO / 3 Ph Square D QO panel. All I am required to do is feed the panels, plus the branch circuits for the freezer, exhaust fan and water heater.
The MDP is 480V.
Based on table 220.56 I have calculated the following:
Fryers 7 x 17KW = 119,000
Griddle 1 x 9KW = 9,000
Sandwich grill 2 x 2.7KW = 5,400
Freezer 1 x 12KW = 12,000
Water Heater 1 x 4.5KW = 4,500
Exhaust Fan 1 x 1.5KW = 1,500
Total 151,400 x 65% (6+ appliances) = 98,410
98,400/ (208 x 1.732) = 273 A
Based off of my calculations it seems a 112.5 KVA transformer would be sufficient. Am I missing something, or have I calculated incorrectly? It just seems as though all of these appliances should require a larger transformer. Also, I realize that based on 220.56 I can use a 65% demand factor, but I know that these units will all be coming on at once and I would assume the fryers will cycle at similar rates. I just don't want to under size the transformer.
Thank you in advance for your help.
