Connecting N Gas Supplies; De-Activating Built-In Gas Guard; Operation Of Co Or N Gas Guard - Thermo Scientific 3110 Operating And Maintenance Manual

Section 6
Factory Installed Options
Connecting N
Supplies
De-activating Built-in
Gas Guard
Operation of CO
Gas Guard
6-6 Water Jacketed CO Incubator
2
Gas
Important When using Nitrogen (N2), the gas inlet labels on the back
2
panel will be different than the standard configuration shown in Figure 6-6
as follows; (from left to right) CO2 INLET, N2 INLET #2, and N2
INLET #1.
The N inlets for a built-in gas guard are located on the rear of the
2
electronics drawer (see Figure 6-6). Using 1/4" ID tubing, connect one of
the N supply tanks to the fitting labeled N2 Inlet #1. Connect the second
2
N supply tank to the fitting labeled N2 Inlet #2. Install 3/8" hose clamps
2
to secure the 1/4" ID tubing to the barbed fittings on the regulator and the
rear of the electronics drawer.
Warning Check for leaks at all connections.
The built-in Gas Guard is turned ON when shipped from the factory. In
addition, the Tank Select for the gas guard is specified as Tank 1 when
shipped. Refer to Section 3, Configuration, to de-activate the Gas Guard
or change the Tank Select from 1 to 2. If the operator does not want to
use the Gas Guard, the incubator functions normally by supplying CO
(or N ) through the CO2 Inlet #1 (or the N2 Inlet #1).
2
or N
With the Gas Guard in operation, the incubator will use the gas supplied
2 2
through CO2 (or N2) Inlet #1 until the pressure drops below
approximately 10 psig. At this time, the Gas Guard automatically switches
to the gas supplied through CO2 (or N2) Inlet #2.
In addition, the incubator automatically changes the Tank Sel in
Configure mode from 1 to 2 to indicate that the incubator is now using
gas supplied through CO2 (or N2) Inlet # 2. If the gas supply to CO2 (or
N2) Inlet #1 is replenished, the incubator will continue to operate using
the gas supplied through CO2 (or N2) Inlet #2 unless the operator
changes the Tank Select from 2 to 1 through the Configuration mode.
Refer to Section 3, Configuration.
An audible alarm and two visual alarms occur on the control panel when
the gas guard switches from one supply to the other. The audible alarm
will sound until the operator presses the Silence key on the control panel.
A visual alarm in the Message Center will read Tank 1 Low while the
audible alarm is sounding, but will be removed after the operator presses
the Silence key.
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