HWH 680 Series Operator's Manual page 11

PREVOST H3-45 LEVEL FLOOR ROOM EXTENSION SEQUENCE
1. Ignition key must be in the "ON" position.
2. Park brake must be set.
3. Turn the room extension control panel key to "ON".
4. Any time the room extension key and ignition key is on, there
is a +12 signal to the air seal valve. The valve will open and
the air will exhaust from the seal.
5. After a 20 second delay, a ground signal will turn the amber
indicator light on the room extension control panel on. The room
extension will not operate until this light is on.
6. Push the Room Extension Control Switch to "EXTEND". This
will send a +12 signal for the pump relay, the room extension
solenoid valves and the lock/unlock solenoid valves from the
control box. A +12 signal turns the red pump on light, on the
room control panel, on when the pump is running.
NOTE: The room control switch must be held in the "EXTEND"
position during the extend sequence. If the room control switch
is released before the sequence is complete, the sequence will
start over from Step 6 when the switch is pushed to extend again.
7. A +12 signal will open the room unlock valve. This valve will
stay open during the complete extend sequence.
8. When the room lock pins are fully retracted, the room unlock
limit switch arrangement will send a ground signal to the control
box. The manifold pressure switch will send a ground signal
to the control box when pump pressure reaches 3000 psi. The
sequence will not continue until both signals are received by the
control box.
NOTE: The room, floor and lock limit switches are not connected
directly to the control box. The individual switches are connect-
ed to a central limit switch indicator box for each room. When the
appropriate limit switches complete a +12 circuit for the limit switch
box, the limit switch box supplies a ground signal to the control
box so the sequence can continue.
OPERATING PROCEDURES
ROOM EXTEND SEQUENCE
9. When both the room unlock limit switches and the manifold pres-
sure switch signals are received by the control box, a +12 signal
will open the room extend solenoid valve.
10. When the room is fully extended, the room out limit switch
arrangement sends a ground signal to the control box. The
manifold pressure switch sends a ground signal to the control
box when pump pressure reaches 3000 psi. The sequence will
continue when both signals are received by the control box.
11. When both the room out limit switches and the manifold pres-
sure switch signals are received by the control box, a +12 signal
will open the floor up solenoid valve.
NOTE: The unlock valve and room extend valve are still open
at this time.
12. When the floor is up in place, the floor up limit switch sends
a ground signal to the control box. The manifold pressure switch
sends a ground signal to the control box when pump pressure
reaches 3000 psi.
13. When both the floor up limit switches and the manifold
pressure switch signals are received by the control box, the pump
will shut off, the room extend valve will close and the floor up
valve will close. The red pump on light will shut off and the se-
quence is complete. The room control switch may be released.
NOTE:
pump shuts off, even if the room control switch is released.
14. The air seal will inflate when the room control key switch
is turned off or if the ignition switch is turned off.
light on the room control panel will go out.
The unlock valve will stay open for 10 seconds after the
The amber
MP36.103A
19JAN00