Instruction Manual
D200158X012
4194S Controllers
July 2018
51
Replacing the Auto/Manual Station
Refer to figures 4‐19, 5-4, and 5-5 for key number locations.
Note
This procedure also permits replacement of the switch manifold O‐rings (key 312), the auto/manual tubing assembly (key 138),
and the frame gaskets (keys 4 and 5).
Disassembly
1. Perform steps 1 through 3 of the replacing case and cover procedure.
2. Loosen the screw (key 316) that holds the auto/manual station (key 273) to the controller frame.
3. Loosen the two screws (keys 314 and 315) that hold the auto/manual station to the auto/manual tubing assembly
(key 138).
4. Remove the auto/manual station from the controller frame.
5. Remove the switch manifold O‐rings (key 312).
6. Carefully loosen the nut on the relay nozzle tubing assembly (key 18) where it connects to the auto/manual tubing
assembly (key 138). Loosen three screws (keys 34 and 131) and remove the tubing assembly and frame gaskets
(keys 4 and 5).
7. Inspect the gaskets (keys 4 and 5) and O‐rings (key 312) for wear. Replace if necessary.
Assembly
1. Install the gaskets and tubing assembly to the frame. Start, but do not tighten, the three screws (keys 34 and 131)
and the nut on the relay nozzle tubing assembly (key 18).
2. Install the three O‐rings (key 312), and secure the auto/manual station to the controller frame with the screw
(key 316) and to the tubing assembly (key 138) with the two screws (keys 314 and 315). Do not tighten any screws.
CAUTION
In the next step, take care to tighten the two screws (keys 314 and 315) evenly. Uneven tightening could damage the
tubing assembly.
3. Position the auto/manual station as far down on the frame and toward the scale as possible. Carefully tighten the
two screws (keys 314 and 315) so that the auto/manual station contacts the three pads on the tubing assembly.
4. Carefully tighten the remaining screws and nuts.
5. Apply air pressure to the controller, and check for leaks.
6. Install the controller assembly in the case. Slide the controller frame down to assure an O‐ring seal at the pressure
connections. Hold the frame in place.
7. Install and tighten the nine screws that hold the controller assembly in the case.
8. Refer to the Flapper Alignment procedure.
Replacing the Switch Body Assembly, Lever O‐Ring, Switch Body O‐Ring, and the Tubing
Assembly