Acom 2100 User manual

ACOM 2100 Transformer Installation
C A U T I O N
After installing the transformer, the weight of the unit is about
30kg, which should preferably be handled by two persons. An
assistant may be needed to hold the amplifier steady during
transformer installation.
Position the amplifier, with the transformer not yet installed, flat on a table near
the place where it will be used. During the process described below, when the
amplifier cover is removed, take care not to torque or twist the chassis nor let
the amplifier stand on edge. Do not lift the unit by only one corner.
Remove the cover by removing all nine M3x6 screws.
Orient the amplifier on the table so that the transformer compartment is in front
of you.
Unplug all five connectors from the Mains board and remove two M3x8 screws
and one M3x6 screw.

Turn the Mains board right.
Take the transformer out of the carton and remove the shipping board. Keep the
board together with the four long screws and all packing for possible future
transportation. For transformer mounting, four shorter screws (metric M6x12)
are provided in a polyethylene envelope inside the same carton.
Move the transformer, using its band handle, into the compartment. Take care
not to damage the wiring or components and position the transformer so that
the captive nuts are aligned with the corresponding chassis holes. Make sure
that the transformer is centered. The transformer screws must be installed NOW
for safe operation.
Put a lock washer and a flat washer on each screw.
Holding its two sides (front and back) simultaneously, pull the amplifier
towards you just far enough that the two outside transformer captive nuts
appear off the table edge. Support the amplifier until your assistant loosely
screws in the two outside transformer-mounting screws. Pull the amplifier a
further 12-13cm (about 5 inches) until the other two captive nuts appear off the
table edge. Keep supporting the amplifier until your assistant loosely screws
them in. After checking that the transformer is centered, tighten all 4 screws.
Now move the amplifier back over the table.

-2
Plug in the filament supply connector.

Plug in two HV Fast-on connectors to the HV Rectifier board
C A U T I O N
Insert the two rubber grommets (readily threaded on each
transformer HV lead) in the intended chassis-wall slots in order to
protect both HV leads from sharp metal edges. Make sure the
grommets fit the slots fully and properly.
Thread the 8 primary leads of the HV-transformer (labeled with numbers 1 - 8)
through the opening in the sub chassis carrying the Mains PCB.

-3
Turn the Mains board back to its original position, pull out the 8 wires carefully,
and tighten the holding screws.
From the voltage selection table shown below, select the row matching your
nominal mains voltage. Connect the 8 labeled HV-transformer primary wires to
the voltage selector terminals accordingly.

The picture shows 240VAC arrangement.
Now find the LV transformer voltage selector on the Mains PCB and arrange the
jumpers there according to the selected table row.
Connect all five connectors you disconnected in the beginning plus two new
connectors from HV transformer.
Replace the cover, reinstall all nine M3x6 screws first loosely, and finally tighten
them properly.
C A U T I O N
If the amplifier is wired for 100-120VAC, do not forget to replace
the two rear panel fuses.