Manual

HZS, TVS
10 MF24 – 3.44
Make a note of the thermocouple connections Type N colour codings are: negative = white,
positive = pink (old models: negative = blue, positive = orange).
Disconnect the thermocouple from its terminal block and withdraw it from its sheath (the narrow-
bore built-in tube) and remove any broken bits of thermocouple.
Bend the new thermocouple carefully to match the shape of the original (working from the
terminal end). Should the overall length differ from that of the original provided, ensure that the
tip ends up the same distance from the end as it did in the original.
Insert the new thermocouple into position, restoring any removed porcelain spacers, and ensuring
correct polarity.
Re-assemble the furnace.
5.6 Fuse Replacement
Fuses are marked on the circuit diagram (section 0) with type codes, e.g. F1, F2. A list of the
correct fuses is given in section 8.1. The fuses fitted depend on model and voltage.
If any fuse has failed, it is advisable for an electrician to check the internal circuits. Replace any
failed fuses with the correct type. For safety reasons do not fit larger capacity fuses without first
consulting Carbolite.
The fuses are near the cable entry point, with access by removal of the control box back panel.
5.7 Element Replacement
Please see safety note 5.2 - please wear a face mask.
HZS and TVS with far hinge: Remove the three screws from each end and lift out the half-circular
insulation assembly. Make a plan of all the cable connections and disconnect the cables.
Remove the thermocouples by withdrawing them from the sheaths built into the elements. Remove
the plates through which the element tails are located. Remove the keep plates from each side of
the insulation assembly. Lift out the element to be replaced; save any insulation sleeves for
possible reuse.
Bend or cut the new element tails as necessary, and fit any insulation sleeves; feed the tails through
and fit the element into place.
Refit the keep plates on each side. Refit the tail termination plates, ensuring that the element tails
do not touch any metal parts. Refit the thermocouples and cnnect all the wiring according to the
plan previously made to complete the reassembly.
Check that the furnace is controlling properly to rule out the possibility that the element failed
because of a fault in the control system.
HZS & TVS Elements each element is a half-cylinder
HZS & TVS 12/600
200-240V
4 pairs in parallel,
each pair 2 in series
100-120V
8 elements in parallel
HZS & TVS 12/600E
(equal zones)
200-240V
3 pairs in parallel,
each pair 2 in series
100-120V
6 elements in parallel
HZS & TVS 12/900
200-240V
5 pairs in parallel,
each pair 2 in series
100-120V
10 elements in parallel
HZS & TVS 12/900E
(equal zones)
200-240V
6 pairs in parallel,
each pair 2 in series
100-120V
12 elements in parallel
12/600 has 4 pairs of 150mm length; 12/600E has 3 pairs of 200mm length
12/900 has 2 pairs of 150mm (ends) and 3 pairs of 200mm (centre)
12/900E has 6 pairs of 150mm elements;
Where both 200mm and 150mm are fitted, the 150mm elements are at the ends.