Carbolite PTC 12/20/150 - Manual (Page 15)

PTC
MF11 – 3.08 15
8.0 C IRCUIT D IAGRAM
8.1 Circuit Diagram
9.0 F USES & P OWER C ONTROL
9.1 Fuses
Supply Fuses: 32mm x 6mm type F1 (quick blow)10 Amp. Access by removal of the furnace back
panel.
Protection Fuse: 20mm x 5mm type FF (ultra rapid) 10 Amp. Access by removing the holder
underneath the furnace, using a screwdriver.
The purpose of the Protection Fuse is to ensure immediate power cut off if the voltage change
switch is in the 115V position and the furnace is connected to a 220-240V supply.
9.2 Power Control
In this model the same heating element is used for 110-120V models and 220-240V models.
Changing between the voltages is by the switch underneath the furnace – see section 2.2.
The correct power limit setting (parameter OP.Hi ) for the furnace for all voltages is 100%.
Instrument Switch
temperature
controller
thermocouple
SSR
e
l
e
m
e
n
t
heat
on
Supply
Fuses
N
L
PE
temperature
indicator
thermocouple
e
l
e
m
e
n
t
voltage
change
switch
(shown in
230V
position)
Protection
Fuse