NuAire NU-5800, Operation And Maintenance Manual

Page: 16 / 48

OM0211 Page 16 of 48
Rev 3 March 2013
7.6.1 CO
2
Tube Connection
Included with the Incubator are a tubing kit consisting of (1) six foot (2m) vinyl tube and (1) 50mm polypropylene
0.3 micron HEPA filter. The filter is an extra for your convenience. Hook one end the six foot tube to the fitting
labeled CO2 (20 psi) on the back component panel of the incubator. Then hook the other end on the outlet of the
2 stage regulator located on the gas supply. You can locate the CO2 supply filter on bottom right of the front panel
behind the hinged valance at the bottom of the outer door. The filter is labeled CO2 filter. To open the valance the
outer door must be open. Reach in under the front of the valance and pop it open by pulling it toward yourself.
The Filter supplied in the shipping kit is an extra one that can be used when it is time to change the one on the unit.
Please see the Maintenance section for the proper period to change the filter.
7.6.2 CO
2
Supply
• CO
2
of medical grade is recommended.
• A two-stage pressure regulator, Linde # 19590, or equal, is recommended.
• DO NOT USE a single stage regulator.
It will not give a stable output at 20 psi and exposes the Incubator to the gas cylinder pressure.
7.6.3 CO
2
Regulators
The regulator’s high-pressure stage direct from the supply cylinder must have a range of from 0 to 2000 PSI or
0 to 140 BAR. This gauge indicates actual tank pressure. The low-pressure stage should have a range of 0 to 30 PSI
or 0 to 2 BAR (100 PSI or 6 BARS maximum). This gauge will indicate the actual CO
2
pressure to the Incubator. Some
single stage CO
2
pressure regulators have two gauges. USE A TWO-STAGE REGULATOR. All NuAire Incubators use
CO
2
in such small quantities that precise metering of CO
2
input pressure is important for maximum performance.
To connect the regulator:
First: Open the CO
2
cylinder slightly, for an instant (this is termed “cracking the valve.”)
This will blow out dust or dirt that may have collected in the valve outlet.
BE SURE to keep your face away from the valve outlet to protect your eyes from dust or dirt.
Second: Make sure the regulator pressure-adjusting screw is released by turning it counterclockwise
until it turns freely.
Third: Attach the regulator to the cylinder valve and tighten the connection nut with a wrench.
BE SURE DISC SEAL IS IN PLACE BEFORE MAKING CONNECTION.
7.6.4 CO
2
Connection
Connect the CO
2
supply from the low-stage of the two-stage regulator, to the inlet fitting located on the Incubator
back panel labeled “CO2 tank 1”. The filter should be inserted downstream of the low-stage regulator before the
inlet fitting on the Incubator as shown in the figure. Secure each connection with the clamps supplied. Observe
proper flow orientation of the filter (look for “in” or a green dot on the filter). The tubing is easily cut with a sharp
knife.
7.6.5 CO
2
Supply Adjustment
With the regulator OFF (i.e. fully counterclockwise), open the cylinder valve slowly usually 1 to 2 turns is sufficient.
NEVER STAND IN FRONT OR BEHIND THE REGULATOR WHEN
OPENING THE VALVE. ALWAYS STAND TO ONE SIDE.
The cylinder tank pressure should read 700 to 800 PSI or 48 to 55 BAR, more or less, depending on the temperature
of the cylinder. Next, turn the regulator’s pressure adjusting screw clockwise, until the low-pressure gauge reads
20 PSI or 1.4 BAR. The CO
2
connection is now complete.
Note: OSHA requires the CO
2
tanks to be physically restrained (i.e. via chained to wall)
to prevent accidental damage to cylinder.
7.6.6 Checking the Connections
The connections can be checked for leakage by brushing a small amount of soapy water on each one.
Observe to see if any bubbles are blown. If not the connection is secured properly.
If it is, the cause of the leaking needs to be determined, (i.e. loose clamp or damaged hose) and corrected.
CAUTION
!
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