Technical Data and Specifications 6-4
Revision 2 - 26 April, 2000 HP SERIES DIMMER TECHNICAL MANUAL
6.4 “Engine Block” removal
1. Remove the sixteen lid screws and the lid.
2. Remove all 24 wires [12 wires on HP6] to the circuit breakers.
3. Remove the screws holding the front panel in place (3 underneath, 2 pairs each
side).
4. Disconnect the flat cable from the CPU card to Output card and remove the front
panel assembly.
5. Disconnect the wires from the output card to the output connectors.
6. Disconnect the mains input wiring from the terminal block.
7. Remove three screws each side securing the engine block to the side of the chassis.
8. Remove the three nuts front and rear securing the engine block to the chassis
9. Lift out the engine block vertically, gripping the front and rear edges of the output
circuit card.
Re-assembly involves carrying out the above operations in reverse order.
NOTES:
The Output card is fastened to the engine block by fifteen screws, plus the triacs/SCRs
and the fan control transistor.
The fan control transistor is insulated from the heatsink by a mica sheet and a plastic
shoulder washer under the screw head.