Pressure Low Indicating Lights
The two red indicating lights, labeled Pressure Low, show when a supply
tank is depleted. If both tanks are depleted, both red indicating lights
will be lighted.
Voltage Select Switch
(refer to Figure 2-1)
The VOLTAGE SELECT switch, on the back of the unit, permits the
selection of the proper electrical line voltage (115V or 230V).
Caution
Make sure to set the switch to the correct voltage before
connecting the unit to power.
s
Remote Alarm Contact
(refer to Figure 2-1)
A SPDT relay is provided for monitoring alarm conditions on the Gas
Guard. Connections are made by means of an RJ-11, telephone style
jack, located on the back of the unit. Figures 3-2 and 3-3 show the con-
nector wiring diagram. A power outage or low gas pressure on the Gas
Guard will activate the relay.
A modular to modular cable, part no. 190388 and an RJ-11 telephone
style terminal converter, part no. 190392 or equivalent may be used to
convert to a screw terminal connection. Refer to the above illustration.
3-2
Model 3050/3052
Thermo Scientific
Section 3
Control and Indicating Devices
(2) COM
(4) N.C.
(3) N.O.
ALARM CONTACTS
30V MAX / 1 A MAX
Common (YEL) 5
N.O. (GRN) 4
N.C. ( RED) 3
not used (BLK) 2
(BLK) 2
(RED) 3
(GRN) 4
(YEL) 5
2 (YEL)
3 (GRN)
4 (RED)
5 (BLK)
Stock # 190388
Modular to Modular Cable, 12 ft.
Standard Telephone 4-Cond. Line Cord
(Note Crossed Pinning)
Stock # 190392
RJ-11 to Screw
Terminal Converter
Figure 3-2.
Connections
Figure 3-3.
Wiring
