Catalogue

UNT-PRC001-EN 55
Electrical Data
Minimum Circuit Ampacity (MCA) and Maximum Fuse Size (MFS) Calculations
for Fan-Coils with Electric Heat (Single Phase)
Heater Amps = (Heater kW x 1000)/Heater Voltage
Note: Use 120 V heater voltage for 115 V units. Use 240 V heater voltage for 230 V units.
MCA = 1.25 x (heater amps + all motor FLAs)
MFS or HACR Type Circuit Breaker = (2.25 x Largest Motor FLA) + Second Motor FLA + Heater Amps
(If Applicable)
HACR (Heating, Air-Conditioning and Refrigeration) type circuit breakers are required in the branch
circuit wiring for all fan-coils with electric heat.
See Table 39, p. 56 through Table 41, p. 56 for motor FLAs.
Select a standard fuse size or HACR type circuit breaker equal to the MCA.
Use the next larger standard size if the MCA does not equal a standard size.
Standard Fuse Sizes are: 15, 20, 25, 30, 35, 40, 45, 50, 60 amps
Fan-coil electric heat MBh = (Heater kW) (3.413)
Table 37. Electric heat (kW)
Unit Size Unit VoltagekWkWkWkWkWkWkWkWkWkWkW
02 115 1.0 1.5 2.0
230 1.0 1.5 2.0
277 1.0 1.5 2.0
208 0.8 1.1 1.5 1.9
03 115 1.0 1.5 2.0 2.5
230 1.0 1.5 2.0 2.5
277 1.0 1.5 2.0 2.5
208 0.8 1.1 1.5 1.9 2.3
04 115 2.0 2.5 3.0
230 2.0 2.5 3.0
277 2.0 2.5 3.0
208 1.5 1.9 2.3 3.0
06 115 2.0 3.0
230 2.0 3.0 4.0 5.0 6.0
277 2.0 3.0 4.0 5.0 6.0
208 1.5 2.3 3.0 3.8 4.5 5.3
08 115 2.0 3.0
230 2.0 3.0 4.0 5.0 6.0 7.0
277 2.0 3.0 4.0 5.0 6.0 7.0
208 1.5 2.3 3.0 3.8 4.5 5.3 6.0
10 115 3.0
230 3.0 4.0 5.0 6.0 7.0 8.0
277 3.0 4.0 5.0 6.0 7.0 8.0
208 2.3 3.0 3.8 4.5 5.3 6.0
12 115 3.0
230 3.0 4.0 5.0 6.0 7.0 8.0 10.0
277 3.0 4.0 5.0 6.0 7.0 8.0 10.0
208 2.3 3.0 3.8 4.5 5.3 6.0
Table 38. Electric heat (kW), low vertical units
Unit Size Unit Voltage kW kW kW kW
03 115 1.0 1.5 2.0
04 115 1.0 1.5 2.0 2.5
06 115 1.0 1.5 2.0 2.5
Note: Low vertical units are only available with electric heat in combination with the two-row cooling coil.
UNT-PRC001-EN.book Page 55 Tuesday, May 8, 2012 10:54 AM