2 IEC Electrical Apprenticeship Curriculum - First Year
T1
T5
2P CB
T2
T6
120/240 V
T3
T7
Panel LB
Forced-Air
Figure 115.342 Heating Unit
T4
AA
Four equally rated
heating elements are
contained in a forced
air-heating unit. These
are sometimes called
FBUS (Fan Blower
Units) because a
blower motor forces
air over the heating
elements to provide
heated air for a room.
calculations will not include any power requirements for the blower motor in the FBU. The nameplate on
the FBU indicates that it will deliver a total of 11.2 kW of heat when the supply circuit is 250 volts.
5. Refer to the illustration of the FBU and the information shown with Figure 115.342. The "hot" resistance
of Element 3 (R) is. ohms.
a. 1.2857
Defont th
b. 1.3951
EDU
c. 5.5804
d. 5.1429
e. 4.7246
shown with Figure 115.342. When operated