Carbolite RHF Series 3 litre - 35 litre - Manual (Page 3)

RHF
MF07 – 3.10
3
connection to the furnace chimney as this causes excessive airflow through the chamber and
results in poor temperature uniformity.
2.3 Heating Elements
The Silicon Carbide elements are VERY FRAGILE and are packed separately. Fit them according to
the instructions in section 5.7.
2.4 Electrical Connections
Connection by a qualified electrician is recommended.
Models RHF 14/3, 15/3, 16/3 and 14/8 may be ordered for single phase use or for two phases out
of a three phase supply with neutral. All other models may be ordered for single phase use or for
three phase with or without neutral. The furnace must be connected only to the type and voltage of
the supply for which it was ordered.
Check the furnace rating label before connection. The supply voltage should agree with the voltage
on the label, and the supply capacity should be sufficient for the amperage on the label.
The supply should be fused at the next size equal to or higher than the amperage on the label. A
table of the most common fuse ratings is also given in section 8.1 of this manual. Where a supply
cable is present there are internal supply fuses; in this case customer fusing is preferred but not
essential.
Furnace with supply cable: either wire directly to an isolator or fit with a line plug.
Furnace without supply cable: a permanent connection to a fused and isolated supply should be
made to the internal terminals after temporary removal of the furnace back panel.
Connection by line plug: the plug should be within reach of the operator, and should be quickly
removable.
Connection to isolating switch: this should operate on both conductors (single phase) or on all live
conductors (three phase), and should be within reach of the operator.
The supply MUST incorporate an earth (ground).
ELECTRICAL CONNECTION DETAILS supply type
Supply Terminal label Cable colour Live-Neutral Reversible or Live-Live
1-phase L Brown To live to either power conductor
N Blue To neutral to the other power conductor
PE Green/Yellow To earth (ground) to earth (ground)
supply Terminal label Cable colour
2- or 3-phase L1 Black to phase 1
L2 Black to phase 2
L3 Black to phase 3 except 2-phase
N Light Blue to neutral except delta
PE Green/Yellow to earth (ground)
Technical Notes
The furnaces covered by this manual have electronically controlled power limits. Do not attempt to
calculate the Amps from the Wattage. High break capacity fuses should be used. Avoid fast-blow
fuses and magnetic trip circuit breakers - consult Carbolite if in doubt.
Two-phase models use two phases out of a 3-phase+neutral supply. One phase is unused. The
neutral current is equal to the current in one of the used phases.
Model RHF 16/35 has unequal phases: L1 and L2 have 4 heating elements and L3 has 2 elements.
In 4-wire configuration, one phase takes half the current of the other two, and the neutral also takes
this half-amount (see also section 8.1).