Carbolite GHA Installation, Operation & Maintenance Instructions Manual page 5

2.5 Electrical Connections
Connection by a qualified electrician is recommended.
All furnaces covered by this manual may be ordered for single phase A.C. supply, which may be
Live to Neutral non-reversible, Live to Neutral reversible or Live to Live. The 2-element models
(-/300) can be supplied for use on two phases of a 3-phase+N supply, and the 3-element models
(-/450) for three phases of a 3-phase+N supply or a delta supply up to 240V. From -/600 upwards
all the G-range are made with "universal" wiring, such that they may be reconfigured between
1phase, 3-phase+N and 3-phase delta. They are, however, factory set to the ordered supply.
Check the furnace rating label before connection. If the supply voltage and phase does not agree
with the rating label, then read section 2.6 – it may be possible to reconfigure the furnace and/or
adjust the power.
The supply should be fused at the next standard size equal to or higher than the design amperage.
See section 8.1. Where a supply cable is present there are internal supply fuses, in which case
customer fusing is preferred but not essential.
If a supply cable is fitted it may be connected to an isolator or fitted with a line plug. Where no
supply cable is fitted a permanent connection to a fused and isolated supply should be made to the
internal terminals after temporary removal of the furnace back panel. A line plug should be within
reach of the operator, and should be quickly removable. An isolating switch should operate on
both conductors (single phase) or on all live conductors (three phase), and should be within reach
of the operator.
CONNECTION DETAILS
Supply Terminal label
1-phase
supply Terminal label
2- or 3-phase
The supply MUST incorporate an earth (ground).
2.6 Reconfiguring and Adjusting for Voltage.
In the instructions below, "controllers" means the single element controller in the single zone
modes, or the three element controllers in the 3-zone models. The overtemperature controller
(where fitted) is not affected.
Models –/300
The standard single-phase models can operate over the voltage range 200V-240V. The 2-phase
models can operate over the range 380/220V to 415/240V. The furnace is wired according to the
original order and conversion from 1-phase to 2-phase is not possible. To check for voltage setting
within the appropriate range, or to change to another setting, follow the instructions in section 8.2.
Models –/450 (1-phase)
The standard single-phase models can operate over the voltage range 200V-240V. The 3-phase
models can operate over the range 380/220V to 415/240V. The furnace is wired according to the
original order and conversion from 1-phase to 3-phase is not possible. To check for voltage setting
within the appropriate range, or to change to another setting, follow the instructions in section 8.2.
MF48 -1.18
Cable colour
L Brown
N Blue
PE Green/Yellow
Cable colour
L1 Black
L2 Black
L3 Black
N Light Blue
PE Green/Yellow
supply type
Live-Neutral Reversible or Live-Live
To live to either power conductor
To neutral to the other power conductor
To earth (ground) to earth (ground)
to phase 1
to phase 2
to phase 3 except 2-phase
to neutral except delta
to earth (ground)
G range
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