Forma Series II 3110 Water-Jacketed co2 Incubators User Manual

Replacing O
2
Sensor -
Models 3130/3131, 3140/3141
Figure 5-10. Water Jacket Drain and Hose Barb Insert
5. After water jacket has finished draining,
remove the hose barb insert and secure on
the front of the unit. See Figures 5-10
and 5-11.     
6. Install cover plate. 
7. To fill the water jacket, see Section 1. Be sure to add the rust inhibitor
to the water when filling. For the proportions of rust inhibitor to water
and the part number, see Section 5.
The O
2
sensor output declines over time, even if the unit is not in use.
Replace the sensor every 30 months to ensure consistent output and to
prevent the possibility of failure in the middle of a test experiment.
The O
2
sensor is located on the blower scroll plate in the chamber of the
unit. To replace it, refer to Figure 5-12 and 5-13 and follow the steps
below.
1. Turn the unit off and disconnect the plug from the power source.
2. Remove the top duct by removing 2 wingnuts.
3. Locate the sensor on the scroll plate.
Water Jacketed CO2 Incubator        5-11
Thermo Scientific
Section 5
Routine Maintenance
Figure 5-11. Hose Barb Insert
O
2
Sensor Fuel Cell -
Models 3130/3131, 3140/3141
Figure 5-12. Underside View of Top of Chamber
Draining Water
Jacket (continued)

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4. Lift up slightly on the tab securing the sensor
wire terminal connection. Be careful not to
break the tab off. See enlarged detail of Figure
5-13.
5. Disconnect the terminals from each other. Note
the orientation of the terminals.
6. The O
2
sensor is screwed into the brass fitting.
Unscrew the old sensor and discard.
7. Screw the new sensor in firmly. Be careful not to
cross-thread.
8. Orient the terminals as previously and connect.
9. Install the top duct and tighten the 2 wingnuts.
10. Plug the unit in. Calibrate the O
2
system using the O
2
CAL@20.7%
method as described in Section 2.
11. Allow the unit to run until the temperature stabilizes. Check the O
2
and CO
2
operation and return the unit to service.
The Model 3100 Series incubators are shipped from the factory with a rust
inhibitor added to the water in the jacket. This inhibitor must be
replenished every 2 years. Mix 1 bag/bottle of the rust inhibitor with a
gallon of distilled, de-mineralized, or de-ionized water. Drain a gallon of
water from the jacket and replace it with the rust inhibitor mixture.
Rust Inhibitor (0.5 lb.) bag
1900100
Rust Inhibitor (800ml) bottle
1900101
(use in units with a cooling coil)
5-12
Water Jacketed CO2 Incubator
Thermo Scientific
Section 5
Routine Maintenance
Figure 5-13. Detail
Adding /Replenishing
Rust Inhibitor
Replacing O
2
Sensor
(continued)

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Section 6  
Factory Installed Options
A set of relay contacts are provided to monitor alarms through an RJ-11
telephone style connector on the back of the cabinet. Refer to Figure 1-13
for the location of the alarm connector.
The remote alarm provides a NO (normally open) output, a NC (normally
closed) output and COM (common). Refer to Figure 6-1.
The contacts will trip on a power outage or an over temperature condition.
The contacts may also be programmed to trip or not trip on temperature
alarms, CO
2
alarms, O
2
alarms, and RH alarms. See Section 3, System
Configuration. 
Water Jacketed CO
2
Incubator        6-1
Thermo Scientific
Figure 6-1. Contacts
Remote Alarm
Contacts

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Connecting Analog
Output Boards 
All incubator models can be purchased with the RS485 communications
option. This option allows the incubator to be directly connected to a
Model 1535 alarm system without the use of a communications module. A
junction box is provided with each RS485 option. Refer to Figure 6-2 for
wiring details.
To allow the incubator and the 1535 to communicate, an address must be
allocated on the 1535. Refer to Section 5.8 of the 1535 operating manual.
The same address number must be assigned to the incubator. Refer to
Section 3 of this manual, System Configuration.
Warning The electronics drawer contains hazardous voltages. Opening the
drawer and/or wiring in an analog board should be performed by qualified
personnel only. 
▲
The analog output board option allows the incubator to output analog
signals representing the air temperature of the cabinet, the CO
2
content ,
the O
2
content, and the relative humidity, depending upon which systems
are in the incubator. There are three different analog output board options
available : 0-1V, 0-5V, or 4-20mA signals. Negative display readings will
output 0V. The outputs do not have isolated grounds. See Table 6-1 for
output specifications of the three boards.
6-2
Water Jacketed CO
2
Incubator
Thermo Scientific
Section 6
Factory Installed Options
Figure 6-2. Wiring
Connecting the RS485
Interface (190523)

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Water Jacketed CO
2
Incubator        6-3
Thermo Scientific
Section 6
Factory Installed Options
Table 6-1. Analog Output Board Specifications
For the 0-1V and 0-5V boards, the recording device must supply a load
>/=1000 ohm. For the 4-20mA board, the recorder must supply a load of
To wire in the analog output board, a 22-gauge, 3-conductor wire with a
shield (Part # 73041) is recommended, maximum length 50 ft (15.2m).
This is readily available from other vendors including Alpha Part #2403,
and Deerborn Part # 972203.
Warning Accuracy of the output at the board terminal strip to the
incubator display is ±1 unit. There is no calibration from the incubator.
Calibration to the incubator display must be at the instrument connected
to the output board. 
▲
1. Turn off the incubator’s power switch and unplug the power cord from
the wall outlet.
2. Open the exterior cabinet door and remove the two screws shown in
Figure 6-3.
190512 4-20mA 
Output Scaling 
4-20mA Equals
190544 0-1V 
Output Scaling 
0-1V Equals
190543 0-5V 
Output Scaling 
0-5V Equals
Temp
00-100°C
0.0-100°C
0.0-100°C
RH
0-100%RH
0-100%RH
0-100%RH
CO2
0.0-100.0%CO@
0-100.0%CO2
0-100.0%CO@
O2
0.0-100.0%O2
0-100.0%O2
0-100.0%O2
Figure 6-3. Screw Locations

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