11
FIGURE EIGHT: BOILER SUPPLY USING EXISTING CONSUMER UNIT
N
E
L
N R E N L
CONN1
CONN5
CONSUMER UNIT
MCB MCB
MCB
AIR
GAP
PUMP
ELECTRIC BOILER
N
L
MAINS SUPPLY
DOUBLE POLE
RCD OR DOUBLE
POLE ISOLATION
LOCAL TO BOILER
DOUBLE POLE
ISOLATION SWITCH
OR DOUBLE POLE
RCD
3A FUSED
SPUR OR MCB
HEAT RESISTANT
CABLE
DEMAND SIGNAL
FROM CONTROLS/
PROGRAMMER ETC
(SEE TYPICAL
WIRING DIAGRAMS)
TO CONTROLS
PROGRAMMER / ETC
EARTH BONDING
TO BE PERFORMED
IN ACCORDANCE
WITH BS7671
BOILER SUPPLY
MCB
L
N