Bradford-White Corp BWCV warranty Troubleshooting Copper Brute II Controls, Bradford White

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Page 36 Bradford White

8.6 Troubleshooting Copper Brute II Controls

The Copper Brute II series consists of two 2- stage models (500 and 750), one 3-stage model (1000), and four 4-stage models (1250 to 2000). The 2-stage models have one ignition module, and the 3- and

4-stage models have two ignition modules capable of independent operation.

A diagnostic panel, that includes test points, as well as diagnostic lights, is provided in the control module. It is located on the right side of the module, behind the display. To access, remove the retaining screws from the display cover panel and remove it. Grasp the control module at its base and pull it outward. Ladder diagrams are shown in Figures 18 through 20. Voltage test points on the diagnostic panel are indicated by solid circles connected by short diagonal lines.

Figure 18 shows the diagram for the 2-stage models 500 and 750. These have one blower and one ignition module. The blower is energized directly through the “inducer” terminals F1 and F2 of the (Fenwal) ignition module. The 24V power to the 2nd stage gas valve is routed through the 1st stage VALVE terminal, so that stage 2 cannot fire unless the stage 1 gas valve is open. The 750 differs from the 500 only in that the 750 has two gas trains in stage 1, while the 500 has only one.

The ladder diagram for the model 1000 is shown in Figure 19. Ignition module #1 handles stages 1 and 2, and ignition module #2 handles stage 3. The single blower is energized directly through the “inducer” terminals of either ignition module. The 24V power to the T’STAT terminal of both ignition modules is routed through the safety interlocks.

The ladder diagram for models 1250 to 2000 is shown in Figure 20. These 4-stage models have two ignition modules, each with its own blower, and each controlling 2 stages. The blowers are energized by the ignition modules indirectly via switching relays. When either ignition module receives a call for heat, it switches its blower to high speed and the blower of the idle ignition module to low speed.

The wiring schematics for the Copper Brute II 500 – 1000 are shown in Figure 21, and the schematics for the 1250 to 2000 are shown in Figure 22. All 24V wiring is routed through the diagnostic PC board. Wiring harnesses connect between the diagnostic PC board and the control components, indicator board, or field wiring terminal strip. The diagnostic board contains LEDs that indicate open status of the safety interlocks, and quick-connect terminals that provide tests points for checking voltage/continuity at various points in the control circuit. Line-voltage connections are routed via the line-voltage terminal buss.

Certain control elements that may need to be re-wired in the field are connected via the field wiring terminal strip rather than to the diagnostic PC board. These include the low-water cutoff (LWCO), water flow switch, and inlet/outlet water temperature sensors.