5.5 Removing the Top Section
If it becomes necessary to remove the top of the incubator
to move it through a low doorway, do the following:
1. Read the instructions completely before starting.
2. Provide adequate space and sufficient lighting to per-
form the work.
3. Disconnect the inlet water supply and the drain.
4. Before lifting the top section from the incubator, provide
carpenter’s horses or other suitable support when the top
is suspended.
5. Remove all test material from the incubator chamber.
6. All temperature and/or humidity sensing probes are
mounted on a probe mounting bracket on the right side
of the incubator chamber. Remove the nuts securing the
bracket and then remove the probes from the bracket.
Note the location and configuration of the probes.
7. The sensing bulb capillaries are routed behind the duct
sheet up to the access port at the top of the unit behind
the control panel.
Note:
Route all the probes between the duct sheet and the out-
side wall of the chamber so that when the top is raised, all
probes will move freely up and out. do not kink or bend the
capillaries.
8. The humidification system drain line (3/8” clear tygon)
is routed down through the access port and is secured to
the condensate drain tube on the center left side of the
incubator (as viewed from the rear). Free the drain line,
by pulling it away from the float tank (behind the con-
trol panel) and routing it down through the access port.
9. Open the control panel by removing the two screws
located on the left side of the control panel.
10. Loosen the top gasket around each of the air exhaust
vents by turning the screw.
11. Remove the eight screws from the top cover of the incu-
bator.
12. Remove the four screws from each of the vent caps on
the top cover of the incubator. The top cover can now be
removed.
13. Remove the nine 5/16” x 4” hex head bolts, lock wash-
ers, and two flatwashers which secure the top assembly
to the cabinet. Note the washer arrangement on the
bolts.
14. Remove the black trim gasket located at the junction of
the top assembly and the main incubator section. The
ends of the gasket have been joined together at the rear
of the incubator.
Note:
When raising the top section, notice the gasket seal at the
top opening of the incubator chamber. The gasket must be cor-
rectly positioned when reinstalling the top on the chamber.
15. Slowly lift the entire top assembly up and off the lower
chamber section while carefully guiding the capillaries
and sensing bulbs out of the chamber area. Place the top
assembly onto the carpenter’s horses or other support
arrangement.
16. Reinstall the top assembly by reversing the above proce-
dure. Exercise care particularly when:
•
Placing and aligning the sealer gasket on the 1/2”
flange on top of the chamber when lowering the top in
place.
•
Routing the temperature and/or humidity sensors and
capillaries to prevent severely bending them.
•
Mounting the temperature and/or humidity sensor
bulbs on the mounting brackets.
•
Tightening the top mounting bolts alternately to ensure
a balanced pressure on the gasket.
5.6 Setting the Door Heater Control
High voltage is present behind con-
trol panel. Servicing must be per-
formed only by qualified electrical
service personnel.
The infinite heater control is
located in the right side of the incu-
bator top compartment behind the
control panel door. The heater
varies the amount of door heat from
no heat (zero) to full heat (100) as
indicated by the control dial face. If
the knob is turned past zero, a
“click” will indicate that all power
to the door is shut off. If turned past
100, a similar “click” will indicate that the heat is set at the
maximum.
Initially the units leave the factory with the dial set at 40.
If desired, the amount of heat can later be reduced until mois-
ture appears on the door, then the heat advanced. However, in
fluctuating ambient conditions, it is recommended that a mini-
mum of 40% door heat be used.
Models 3940 and 3949 _____________________________________________________________________________Service
5 - 2
Figure 5-1