Lake Shore Model 331 Temperature Controller User’s Manual
4.15.2 Relays (331S Only)
There are two relays on the Model 331S numbered 1 and 2. They are most commonly thought of as
alarm relays, but may be manually controlled also. Relay assignments are configurable as shown in
Figure 4-6.Two relays can be used with one sensor input for independent high and low operation.
When using relays with alarm operation, set up alarms first. The relays are rated for 30 VDC and 5 A.
Their terminals are in the detachable terminal block on the Model 331S rear panel.
To configure Relay 1 press the Alarm key and press Enter until the following display appears.
Select With °®
Relay 1 A Alarm
Use the
s
or
t
key to cycle through the options for Relay 1: Off, On, A Alarm, or B Alarm. Press the
Enter
key. If the relay is set to follow either the A or B Alarm, the following screen will appear.
Select With °®
Relay 1 High Alarm
Use the
s
or
t
key to cycle through the relay alarm functions: Low Alarm, High Alarm, and Both
Alarms. Press the
Enter
key.
Configuration for Relay 2 is identical to Relay 1.
R
e
lay 1
R
e
lay 1
Off
Off
Manual Off
relay remains in
normal state
High
Alarm
Low
Alarm
Both
Alarms
On
On
Manual On
relay remains in
active state
A Alarm
A Alarm
Follows
Input
A
B Alarm
B Alarm
Follows
Input
B
R
e
lay S
e
ttings
R
e
lay S
e
ttings
R
e
lay 2
R
e
lay 2
Off
Off
Manual Off
relay remains in
normal state
High
Alarm
Low
Alarm
Both
Alarms
On
On
Manual On
relay remains in
active state
A Alarm
A Alarm
Follows
Input
A
B Alarm
B Alarm
Follows
Input
B
Off
Manual Off. Relay remains in the normal state.
On
Manual On. Relay remains in the active state.
A Alarm
Relay will follow Input A alarms.
Both Alarms
Relay active when either the High or Low Alarm is active.
Low Alarms
Relay active only when the Low Alarm is active.
High Alarms
Relay active only when the High Alarm is active.
B Alarm
Relay will follow Input B alarms.
Both Alarms
Relay active when either the High or Low Alarm is active.
Low Alarms
Relay active only when the Low Alarm is active.
High Alarms
Relay active only when the High Alarm is active.
Figure 4-6. Relay Settings
Operation
4-31
