DeVilbiss DeVO/MC44-90 - Service Instructions; Proper Repair Procedures; Cabinet Covers

SECTION 7
SERVICE INSTRUCTIONS
Proper Repair Procedures
The DeVilbiss DeVO/MC44 is designed for ease
of service by utilizing a vertical divider (4 Fig.
15) and accumulator shelf (1 Fig. 15).
Components are situated on the divider and
shelf in such a way as to make them easily
attainable. The service section provides de-
tailed information for troubleshooting and
replacing components within the system.
Also, to aid service personnel, a DeVO Service
Kit (Part #444-501) is available which contains
the necessary gauges, tools, and test instru-
ments to properly service the oxygen concen-
trator. The following parts are included in the
Service Kit.
(1) | 3/16” Slotted screwdriver
(1) #1 Philips head screwdriver
(1) #2 Philips head screwdriver
(1) 13/8” Nut driver
(1) 7116” Nut driver
(1) 6” Crescent wrench
(1) | 8" Duckbill pliers
(1) 5/32" "T“ Handle allen wrench (444-592)
(1) } 9/64” “T“ Handle allen wrench | (444-593)
(1) 3mm “T” Handle allen wrench | (MC29D-645)
(1) | 7/64” “T” Handle alien wrench f (MC44D-710)
(2) 10-30 PS! Pressure gauge and (444-591)
hose
(1) | Toolbox
(10) | Cabinet fasteners
(20) | #2 Hose clamp (444-524)
(20) | #8 Hose clamp (444-537)
(20) | #11 Hose clamp (MC29D-638)
(20) | #12 Hose clamp (444-538)
(2) | Pressure test assembly (444-502)
(1) Pressure test assembly (MC29D-606)
In addition to the Service Kit, an oxygen
analyzer will be needed to check the oxygen
concentration levels. A volt meter may also be
needed when voltage testing is required.
When servicing the DeVO/MC44 be absolutely
certain that the correct tools are used and
parts are free of oil and grease or any
material not compatible with oxygen. Teflon
tape is recommended and must be applied to
13
the male threads omitting the first thread to
eliminate the possibility of tape particles
entering the oxygen system. Loctite “PST”
sealant may also be used in place of teflon
tape.
NOTE: Due to the proximity of the electrical
components within the DeVO/MC44, discon-
nect the AC power cord from the wall outlet
before attempting repairs on the unit. Also,
extra care should be taken if it is necessary to
operate the unit with the cabinet covers
opened.
Cabinet Covers
To open front cover:
1. Loosen the cabinet fasteners at the top
and on the sides of the unit using a 5/32”
allen wrench (See Fig. 9). Fasteners should
be rotated 1/4 turn counterclockwise to
loosen them.
2. Carefully swing the front cover (7 Fig. 10)
to the right to avoid damaging the elec-
trical harness.
To remove front cover completely:
1. Disconnect large quick-connect terminal
(16 Fig. 10) located in main wiring har-
ness.
2. Open back cover and disconnect line cord
from terminal block (6 Fig. 13).
3. Disconnect termina! to 9 volt battery (21
Fig. 11).
4. Remove the 1/16” diameter hose that is
attached to accumulator fitting (2 Fig.
24).
5. Remove hose clamp and hose (8 Fig. 10)
that connects the pressure regulator to
the flow meter. Either end of hose may be
removed.
To open back cover:
1. Loosen the four cabinet fasteners in the
back of the unit using a 5/32” (4 mm)
allen wrench and then pull back cover
away from the unit until the top of the
accumulator shelf (1 Fig. 15) is exposed.
Ensure that undue tension is not placed
on the electrical connections.
By disconnecting the line cord at the
terminal block (6 Fig. 13) and the quick-
connect terminal for the hour meter (4
Fig. 13) the back cover can be removed
completely.
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