TM 5-6640-212-14
(c) Observe WARN and ALARM lights.
b. Using suitable wrench, open union on vacuum line
Both should go on as TEST pushbutton is depressed,
and warning and alarm relays should energize. If not,
c. Remove attaching nuts, washers and bolts
set WARN and ALARM adjustments in accordance with
securing vacuum pump to wall shelf.
paragraphs b. (1) and (2).
d. Remove vacuum pump.
(4) Recorder Output Adjustment. At full-scale
NOTE
meter reading, the recorder circuit can be adjusted to
Do not turn unit on its side, or upside
provide an output of from 25 to 100 millivolts dc, with
down when removing from shelf or
accurate correspondence of voltage output to LEL meter
oil filled pump will discharge oil.
reading throughout the entire meter range. Adjust
4-6. Cabinets. The cabinet drawer slides, located on
recorder output level as follows:
each side of the drawers, (fig. 4-9), contain screws
(a) With external recorder (minimum input
which are set in slotted holes, so that the drawer can be
impedance 100 ohms) connected to recorder terminals
aligned with the cabinet. After heavy use and vibration
of control module (REC + and -), press and hold down
the drawers might become out of line with the cabinet. If
TEST pushbutton.
this occurs, empty contents of drawer. Note which side
(b) Observe recorder response at full-scale control
of drawer is sitting low or high, and approximately by now
module LEL meter reading.
much. Remove attaching screws, nuts, and lockwashers
(c) Turn screw adjuster of REC potentiometer
securing drawer to slides, remove drawer by picking up
(R17 for CD800/830; R36 for CD802/832 Systems) on
the front of drawer and lifting out. If right side of drawer
printed circuit board to set recorder deflection at 100
is low by 1/4-inch, and left side is in alignment with
percent point on recorder graph.
cabinet, loosen right side slide assembly and lift slide
(d) Release TEST pushbutton.
Confirm that
until desired position is obtained; then secure by
indicating meter and recorder return to zero.
tightening attaching screw. Check again with drawer
4-4. Dry Ice Machine.
installed with one screw on each side, if further
adjustment is required remove drawer and repeat above
WARNING
procedure. When proper alignment is complete, install
Wear safety goggles and cloth gloves
all screws, washers and nuts which secure drawer to
while operating the dry ice machine.
slides.
a. Do not make any changes to the adjustment of the
4-7. Electric Heater. Disassembly.
valve in the center of the cover or to the safety valve on
a. Turn unit on its side (fig. 4-10) and remove four
the cover hinge. These valves are set at the factory to
screws securing bottom cover to housing. Remove
give the greatest efficiency and safety.
bottom cover.
NOTE
b. Remove heating board and insulator from housing
During the operation of the machine
and detach wires going to auto-transformer.
there will be an escape of gas at the
c. Loosen setscrew on knob attached to auto-
side and bottom of the machine. This
transformer and remove knob.
is normal and should not be taken as
d. Remove and tag wires from auto- transformer,
a sign that the machine is not
remove green ground wire and nut and bolt from
operating properly.
housing.
b. Repair is limited to the replacement of rubber
e. Remove nut securing auto-transformer to housing,
gaskets, latch and hinge pins, safety valve body, springs
and remove auto-transformer.
and ball.
However, do not attempt repair an
f. Check heater board for broken heater elements.
compressing the seal washer, orifice tube, body out or
Use multimeter to check continuity across heater
the two hex nuts. These parts are set at the factory at
elements.
time of manufacture. If repair is required in this area
g. Check auto-transformer for continuity using
entire machine must be returned to manufacturer for
multimeter, replace parts as necessary.
adjustment.
4-5. Vacuum Pump. Removal.
a. Remove power from circuit breaker to vacuum
pump.
4-11
