A.O. Smith TC-099 - Manual (Page 38)

AOS WPC - Tech Training 37 of 72 Ashland City, TN © 2007
Servicing should only be performed by a Qualified Service Agent
VF BOILER SERVICE MANUAL
PDB - SECTION B
The mid section of the PDB contains the fusing for the following:
F1 Fuse - 10 amp 240 VAC - European Models only
† F2 Fuse - 20 amp 120 VAC - Pump
F3 Fuse - 3 amp 120 VAC - Transformer Primary Winding
F4 Fuse - 10 amp 120 VAC - FCB 4 Power Supply - N/A on VF boilers
F5 Fuse - 10 amp 120 VAC - FCB 3 Power Supply - N/A on VF boilers
F6 Fuse - 10 amp 120 VAC - FCB 2 Power Supply - N/A on VF boilers
F7 Fuse - 15 amp 120 VAC - MCB Power Supply
†. Field installed boiler circulation pumps (VB models): For outputs up to 120 VAC 5 FLA use on board
remote pump relay connected to TB1 terminal board on the PDB (page 36). For 120 VAC outputs between 5
and 20 FLA, use an external relay/starter and supply 120 VAC pump power through the 20 amp F2 pump
fuse on the PDB shown above. For outputs above 120 VAC or 20 FLA use an external relay/starter and a
separate dedicated power supply for the pump, use the on board pump relay Com and N.O. contacts to
initiate the field supplied starter/relay coil only.
B
F2 Fuse - 20 Amp - 120 VAC
Pump Power Supply
F3 Fuse - 3 Amp - 120 VAC
Primary Winding Transformer
F4 Fuse - 10 Amp - 120 VAC
FCB 4 Power Supply
(FCB 4 not used on VF Boilers)
F5 Fuse - 10 Amp - 120 VAC
FCB 3 Power Supply
(FCB 3 not used on VF Boilers)
F6 Fuse - 10 Amp - 120 VAC
FCB 2 Power Supply
(FCB 2 not used on VF Boilers
F7 Fuse - 15 Amp - 120 VAC
MCB Power Supply
F1 Fuse - 10 Amp - 240 VAC
European Models Only