Connection To Remote Alarms; Liquid Nitrogen Level Monitor's Alarm Contact Specifications - Thermo Scientific LOCATOR Operation Manual

A L N
CCESSORY IQUID
Note
The Liquid Nitrogen Level Monitor can
be configured to present your alarm
system with either a normally open
contact or a normally closed contact.
Which mode is currently operative de-
pends on the placement of a single
jumper on the circuit board. For a nor-
mally open contact, the jumper should
be placed on J6. For a normally
closed contact, the jumper should be
placed on J4. (See Figure 2) Verify
that the jumper is set appropriately
for your remote alarm system.
Figure 1
14
L M
ITROGEN EVEL ONITOR
O
PERATION

Connection to Remote Alarms

When connected to your remote alarm system, the Liquid
Nitrogen Level Monitor will alert you to a problem even
when your laboratory is unoccupied. The Liquid Nitrogen
Level Monitor's alarm contacts are activated at the same
time the Monitor's audible alarm sounds (see Micropro-
cessor Functions).
3. Remove the black plug from the side of the
cover. Insert the wires for the remote alarm
through this hole.
4. Connect the remote alarm wires as shown in
Figures 1, 2 and 3.
5. Replace the Liquid Nitrogen Level Monitor's
cover. Resupply power to the Liquid Nitrogen
Level Monitor and to your remote alarm sys-
tem.
Liquid Nitrogen Level Monitor's Alarm
Contact Specifications
The Liquid Nitrogen Level Monitor's alarm contact is a
Photomos type relay.
Contact Form: Type 1 form B
Load Voltage Maximum: 24 Vdc Max
Load Current Maximum: 120 mA
Typical On Resistance: Maximum 26
Remote Alarm wires connect here
(Note polarity.)
-
+
J3
1
J4 J6
1
1
For normally open contact, place jumper here.
For normally closed contact, place jumper here.
Figure 2