PART TWO - INSTALLATION
SECTION 3 - ELECTRICAL CONNECTIONS
Rev. 2-300
Accu4™ Low-range Turbidimeter System
29
3.4 Closed Contact
TTL Input
Four sets of SPDT relay outputs (Relays A, B, C, and D) are
provided at Terminals 1 through 12 on TB2.
The relay out-
puts are not powered.
The line power used to power the
analyzer may also be used to power the control or alarm
devices with these relay contacts. Refer to Figure 2-12 for a
general wiring arrangement. Always check control wiring to
insure that line power will not be shorted by the relay
switching action, and that wiring conforms to local codes.
WARNING:
MAKE SURE THAT LINE POWER IS NOT PRESENT
WHILE CONNECTING WIRES TO TB2 RELAY
TERMINALS.
FIGURE 2-12 Connecting Control/Alarm Device(s) to
Electromechanical Relay(s)
The closed contact TTL input feature of the analyzer en-
ables you to conveniently:
•
Hold the analog outputs at their present values.
•
Hold all CONTROL or ALARM relays at their present
on/off states.
To activate holding the analog outputs and relays, remotely
or locally jumper Terminals 9 and 10 on TB1.
