Section 6 - Factory Options
6.1 Connections to External Equipment
a. Connecting the Remote Alarm Contacts
A set of relay contacts is provided to monitor alarms
through a RJ-11 telephone style connector on the back of the
unit. Refer to Figure 6-3 for the location of the alarm connector.
The 12-foot telephone cord (P/N 190388) and RJ11-to-screw
terminal conversion box (190392) are available through the
Thermo Forma Service department.
The remote alarm provides a NO (normally open) output,
an NC (normally closed) output and COM (common). Refer to
Figure 6-1.
The contacts will trip on a power outage or an overtemper-
ature condition. The contacts may also be programmed to trip
or not trip on temperature alarms and CO
2
alarms. See Section
3.1, Configuration Mode.
Figure 6-1
b. Connecting the RS485 Interface (190523)
All incubator models can be purchased with the RS485
communications option. This option allows the incubator to be
directly connected to a Thermo Forma Model 1535 alarm sys-
tem without the use of a communications module. A junction
box is provided with each RS485 option. Refer to Figure 6-2
for wiring details. Figure 6-3 shows the location of the RS485
connector on the back of the incubator.
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 3.1 of this manual,
Configuration Mode.
Figure 6-2
c. Connecting the Analog Output Boards (190512,
190543, 190544)
The electronics section contains haz-
ardous voltages. Only qualified elec-
trical service personnel should access
this area.
The analog output board is an option that allows the incu-
bator to output analog signals representing the air temperature
and CO2 content of the incubator interior. There are three dif-
ferent analog output board options available: 0-1V, 0-5V or
4-20mA signals. Refer to Table 6-1 for output specifications of
the three boards.
Table 6-1 Analog Output Board Specifications
Note:
Negative display readings will output 0V. The outputs do
not have isolated grounds.
To wire in the analog output board, Thermo Forma recom-
mends wire Part # 73041 which is a shielded 22 gauge, 3-con-
ductor wire. This wire is readily available from other vendors
including Alpha Part #2403 and Deerborn Part # 972203.
Model 3950/3951 __________________________________________________________________________Factory Options
6 - 1
Contains Parts and Assemblies
Susceptible to Damage by
Electrostatic Discharge (ESD)
CAUTION
black
to additional 1535
modules
to additional 1535
modules
(3) yellow wires
(2) orange wires
(1) green wire
Phone cable to incubator RS485 RJ-11 connector
red
1535 Junction
Box
(1) red wire
(1) black wire
190512 4-20 mA
Output Scaling
4-20mA Equals
190544 0-1V
Output Scaling
0-1 V Equals
190543 0-5V
Output Scaling
0-5V Equals
Temperature
0.0-100.0 °C
0.0-100.0 °C
0.0-100.0 °C
CO
2
0.0-100.0 %CO
2
0-100.0 %CO
2
0-100.0 %CO
2
RS 485
ALARM CONTACTS
30V MAX / 1A MAX
RS 485
ALARM CONTACTS
30V MAX / 1A MAX
#2
Co Inject
15 p.s.i. Regulated
(103.4 kPa)
2
#1
CO Inject
15 p.s.i. Regulated
(103.4 kPa)
2
AUXILIARY HOLE
FOR CABLE
Figure 6-3
