Carbolite HTF Series - Manual (Page 13)

RHF & HTF
MF22 3.09
13
7.0 C IRCUIT D IAGRAM
7.1 Single Phase Example - Manual Door & Electric Door Versions
GR/Y Green/Yellow
R Red
TC temperature programmer BU Blue
OTC overtemperature controller P Pink
G Grey
notes: 1. Autowound element transformer shown; an isolating transformer may be fitted.
2. Door actuator circuits may differ from the example shown.
7.2 Three-Phase Models
Each set (pair) of elements has its own transformer, controlled by a thyristor complete with
thyristor fuse. For 3-phase with neutral, supply and control fuses are not fitted on the neutral sides
of the circuits. For 3-phase delta, fuses are fitted on both sides of the circuit.
The control circuit is taken off L1 and N (L1 and L2 for delta supplies).
Control thermocouple
TC
F2
BU R
F2
R
Instrument Switch
24V
Rectifier
5A
Case Cooling Fans
L
GR/Y
PE
F1
F1
F3
Coil
P G
Electric Door models Only
Door Supply
Transformer
1
6
Door
Control
Switch
5
2
4
+
3
Top
Bottom
Limit Switches
-
Element(s)
F3
Heat
Element
Transformer
Thyristor Fuse
Thyristor
Contactor
BU
(if fitted)
Filter
N
Safety
Switch
OTC
O/temp thermocouple
Door
Motor