4 . EL E C T R I C A L C O N N E C T I O N S
The 3KW, 5kW and 7.5kw Heaters can be wired 230v single phase or 400v 3 phase.
All Heaters MUST BE EARTHED.
Due to the heater having
“Fan Over Run” circuitry the heater must not be turned ON and OFF using the mains supply isolator. The
mains supply isolator should only be used in an emergency or if you need to turn off the heater (once cooled down) for long periods.
The heater should be turned off using the thermostat on the back or any other control device. See Section 8 for further information on
the fan over run.
On small units there are 4 x 20mm and 1 x 25mm knockouts on the top or bottom of the heater and an additional 4 x 20mm and 1 x 25mm knockouts
on the back of the heater, If you require a 32mm hole gently open out a 25mm hole using a taper drill or step drill. Be careful you do not touch the
internal electrics when opening up the holes.
On large units there are 3 x 20mm, 1 x 25mm and 1 x 32mm knockouts on the top or bottom of the heater and an additional 3 x 20mm, 1 x 25mm
and 1 x 32mm knockouts on the back of the heater.
4.1 230V SINGLE PHASE (only suitable for OUH2-03, OUH2-05 or OUH2-07 models)
Please make sure you have read the Safety instructions and that you are a suitably qualified electrician before continuing.
Please Note:- Specified cable sizes are for typical installations, correction factors may need to be used when determining actual cable sizes.
Do NOT use power tools to undo or do up terminal screws.
The 2 link plates that need to link between terminals L1 & L2 + L2 & L3 can be found with this instruction leaflet.
Cable Sizes
OUH2-03 3kW - Use minimum 1.5mm² 3 Core Mains Cable (see note
above).
OUH2-05 5kW - Use 4mm² 3 Core Mains Cable (see note above).
OUH2-07 7.5kW - Use 6mm² 3 Core Mains Cable (see note above).
OUH2-10 10kW and above -
DO NOT WIRE SINGLE PHASE
Add the 2 Links between terminals L1& L2 + L2 & L3
Connect Brown / Live Wire
– Terminal L1 of Heater
Connect Blue / Neutral Wire
– Terminal N of Heater
Connect Green/ Yellow / Earth Wire
– Terminal E
of Heater
PLEASE CHECK ALL CONNECTIONS BEFORE TURNING ON AS
INCORRECT WIRING IS NOT COVERED BY THE GUARANTEE
4.2 400V 3 PHASE
Please make sure you have read the Safety instructions and that you are a suitably qualified electrician before continuing.
Please Note:- Specified cable sizes are for typical installations, correction factors may need to be used when determining actual cable sizes.
Do NOT use power tools to undo or do up terminal screws.
Cable Sizes
OUH2-03 3kW - Use minimum 1.5mm² 5 Core Mains Cable (see note
above).
OUH2-05 5kW - Use 1.5mm² 5 Core Mains Cable (see note above).
OUH2-07 7.5kW - Use 1.5mm² 5 Core Mains Cable (see note above).
OUH2-10 10kW - Use 2.5mm² 5 Core Mains Cable (see note above).
OUH2-15 15kW - Use 4mm² 5 Core Mains Cable (see note above).
OUH2-20 20kW - Use 4mm² 5 Core Mains Cable (see note above).
OUH2-25 25kW - Use 6mm² 5 Core Mains Cable (see note above).
Connect Brown / Phase 1 Wire
– Terminal L1 of Heater
Connect Black / Phase 2 Wire
– Terminal L2 of Heater
Connect Grey / Phase 3 Wire
– Terminal L3 of Heater
Connect Blue / Neutral Wire
– Terminal N of Heater
Connect Green/ Yellow / Earth Wire
– Terminal E
of Heater
PLEASE CHECK ALL CONNECTIONS BEFORE TURNING ON AS INCORRECT WIRING IS NOT COVERED BY THE GUARANTEE
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