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Home›Repair guides›Cummins/Onan›Changing Control Accessory Panel (Groups 10-15 and 20-25)

Cummins/Onan — Changing Control Accessory Panel (Groups 10-15 and 20-25)

Repair & overhaul

From a Cummins/Onan service manual — check it applies to your exact model before use.

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Before you start

  • Failure to remove AC power from the automatic transfer switch and to disable the generator set presents a serious shock hazard during this modification.
  • When screw is removed, control accessory panel is loose on bottom. Have someone holding the panel during removal procedures to prevent personal injury.

Procedure

  1. Open automatic transfer switch cabinet door.
  2. Move operation selector switch to STOP.
  3. Remove AC line voltage from the automatic transfer switch.
  4. Disconnect the starting batteries.
  5. Remove the twist-lock disconnect plug and open the control accessory panel.
  6. Remove external wires from TB1, TB2, TB6 and TB9 (if all present), then remove these terminal blocks from mounting.
  7. Hold the flange edge of the control accessory panel's bottom hinge pin with a needle-nose pliers and remove screw from pin with a screwdriver.
  8. Carefully pull outward on bottom of control accessory panel until it clears cabinet.
  9. Lower control accessory panel from cabinet. Top hinge pin will come out with control accessory panel.
  10. Remove the top hinge pin from control accessory panel and install on new panel if required.
  11. Lift up new control accessory panel into cabinet, carefully engaging top hinge pin.
  12. Center the hole on the bottom control panel flange over hinge pin.
  13. Insert the screw in bottom hinge pin and tighten with screwdriver and pliers.
  14. Install the terminal boards on the wall of the cabinet using #6-32 screws and connect loose wire leads as marked.
  15. Close the panel, reconnect disconnect plug, restore AC line voltage, reconnect batteries, set time delays, move selector switch, close cabinet door.

Tools required

Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.

Source: Cummins/Onan service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.

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