Models 3940 and 3949 ________________________________________________________________Installation and Set-Up
Section 2 - Installation and Set-Up
2.1 Location
Locate the unit on a firm, level surface in an area of mini-
mum ambient temperature fluctuation. A minimum of twelve
(12) inches of clearance is required at the top of the incubator
and a minimum of three (3) inches of clearance is required at
the rear of the incubator. This space is necessary to allow ade-
quate air flow around the refrigeration system.
2.2 Water (Humidity System) and Drain Connections
a. Connecting Water Inlet for Humidity System
Do not attempt to operate the humidity system
without filling it with water. The humidification
heater will overheat, and the overtemp safety ther-
mostat will shut the humidification system down.
The humidity reservoir will require approximately one
quart (0.946 liter) of water on the initial filling. For best opera-
tion of the incubator, sterilized distilled, demineralized or de-
ionized water should be used in the humidity reservoir. Water
purity should be in the resistance range of 50K Ohm/cm to 1M
Ohm/cm, or a conductivity range of 20.0 uS/cm to 1.0 uS/cm.
Refer to ASTM Standard D5391-93 or D4195-88 for measuring
water purity.
Distillation systems, as well as some types of reverse
osmosis water purity systems, can produce water in the quality
range specified. Tap water is not recommended as it may con-
tain chlorine, which can deteriorate the stainless steel. Tap
water may also have a high mineral content, which would pro-
duce a build-up of scale in the reservoir. High purity, ultra pure
or milli-q water is not recommended as it is an extremely
aggressive solvent and will deteriorate the stainless steel. High
purity water has a resistance of above 1M Ohm to 18M Ohm.
Even high purity water can contain bacteria and organic con-
taminants. Water should always be sterilized or treated with a
decontaminant, safe for use with stainless steel as well as safe
for the product, prior to being introduced into the humidity
reservoir.
Distilled or de-ionized water used in the humidity
reservoir must be within a water quality resistance
range of 50K Ohm/cm to 1M Ohm/cm to protect
and prolong the life of the stainless steel. Use of
water outside the specified range will decrease the
operating life of the unit and may void warranty.
The water inlet is the 1/8” FPT connection located on the
rear top left corner of the incubator. Water inlet pressure must
not exceed 40 PSI. a manual shut-off valve should be installed
between the main water supply and the incubator.
To prevent mineral buildup on heater coils and
humidity generator walls, it may be necessary to
clean the humidity generator and immersion
heaters with a non-metallic abrasive pad and
flush thoroughly every two to three months. Refer
to Section 5.7, Cleaning and Adjusting the
Humidity Steam Generator.
b. Alternate Water Supply for Humidity System
If an in-house water supply of the required purity range
(50K to 1M Ohm) is not available, an alternate water supply
method can be used. A large vented carboy (5 gal. minimum) of
water in the required purity range can be placed on top of the
unit. Connect it to the 1/8” FPT water inlet fitting, located on
the rear top left corner of the incubator.
IMPORTANT:
The maximum water consumption of this incu-
bator could be as high as 2 gallons per day. When using an
alternate water supply method, it is imperative that the humidity
reservoir not be allowed to run dry, as permanent damage to the
steam generator will result.
c. Connecting the Drain Line
The cabinet’s 3/8” MPT drain line connection is located on
the rear (lower left side) of the cabinet. A P-trap (Figure 2-1) is
included with the unit and must be installed on the connection.
To install the drain connection:
1. Using Teflon pipe thread tape, tape the threads on the
cabinet drain connection.
2. Using an open end adjustable wrench, install the P-trap
onto the connection. Make sure that the trap is posi-
tioned down.
3. Push a piece of 3/8” ID tubing onto the trap and direct
the tubing to a convenient drain. Install a hose clamp on
the tubing, if desired.
Figure 2-1
Cabinet drain P-trap
2 - 1
