Operation – Carbolite TZF Series User Manual
Page 6

1700-1800° Tube
6
MF32 - 3.25
3.0 O
PERATION
The instructions for operating the temperature controller are given in a separate manual.
If the furnace is fitted with a time switch, see also the supplementary manual MS03.
If cascade control is fitted, see the supplementary manual MS07.
3.1 Operating Cycle (CTF models)
The furnace is fitted with an Instrument switch. The switch cuts off power to the controllers and
contactor.
Connect the furnace to the electrical supply.
Operate the instrument switch to activate the temperature controller. The controller becomes
illuminated and goes through a short test cycle.
Adjust the main temperature controller – see the controller manual.
Set the overtemperature controller to a temperature a little (say 15°C) above the maximum setpoint
of program temperature, according to the instructions in the appropriate manual.
Unless a time switch is fitted and is off, the furnace starts to heat up. The Heat light(s) glow(s)
brightly at first, more dimly as the furnace temperature approaches a program setpoint.
If the overtemperature trip operates then an indicator or message in the overtemperature controller
flashes, and the heating elements are isolated. Find and correct the cause before resetting the
overtemperature controller according to the instructions in the appropriate manual.
To turn the furnace off, set the Instrument switch to it’s off position; the controller display will go
blank. If the furnace is to be left off unattended, isolate it the electrical supply.
3.2 Operating Cycle (TZF)
See section 3.3 for a description of the control methods A, B & C.
The furnace is fitted with a combined Supply light and Instrument switch. The light is on
whenever the furnace is connected to the supply. The switch cuts off power to the controllers and
contactor.
Connect the furnace to the electrical supply. The Supply light should glow.
Operate the instrument switch to activate the temperature controller. The controller becomes
illuminated and goes through a short test cycle.
Control methods A & B: Set the slave (end zone) controllers to the desired offset temperature,
usually zero. Set the main (central) temperature controller to the desired setpoint or program. See
section 3.3 and the separate manual(s) for the controller(s).
Control method C: Set the three controllers to the desired temperatures. See the separate
manual(s) for the controller(s).
Set the overtemperature controller to a temperature a little (say 15°C) above the maximum setpoint
of program temperature, according to the instructions in the appropriate manual.
Unless a time switch is fitted and is off, the furnace starts to heat up. The Heat light(s) glow(s)
brightly at first, more dimly as the furnace temperature approaches a program setpoint.
If the overtemperature trip operates then an indicator or message in the overtemperature controller
flashes, and the heating elements are isolated. Find and correct the cause before resetting the
overtemperature controller according to the instructions in the appropriate manual.
To switch the furnace off, set the Instrument switch to off. If the furnace is to be left off, isolate it
from the electrical supply.