Pdb - Power Distribution Board - A.O. Smith 100 Series Service Handbook

PDB - POWER DISTRIBUTION BOARD

The PDB provides connection points for line-input (120 VAC) power, the Boiler Circulation Pump, the
Combustion Blower and the Transformer. The PDB also distributes the Transformer output (24 VAC) power to
necessary locations. It also contains fuses for various Boiler components. The PDB is located on the Control
Panel, see Figure 10 on page 17.
The PDB circuit board has been divided into sections in the illustration below, each section will be covered
in the pages that follow.
C
12
11
10
J2
F1
TB1
1
28
J1
4 5
1 2
Transformer
3
9 6
8 5 2
7 4 1
24 VAC
Output
F2 F3 F4
2 3 4
Servicing should only be performed by a Qualified Service Agent
6
D
3
15 12
14 11
13 10
J3
F5 F6
5 6 7
A
Figure 21
JP1
9 6 3
8 5 2
7 4 1
115 VAC
Output
F7
B
8 9 10