TEMPERATURE CONTROLLER 5002U-P
REF NO: m55A/om/201
Issue NO: 03
Page 8 of 35
2.3 How to connect wires
Before carrying out wiring, turn off the power to the controller and check that the
cables to be connected are not alive because there is a possibility of electric shock.
NOTE:
All wiring must confirm to appropriate standards of good practice and local
codes and regulations. Wiring must be suitable for Voltage, Current and
temperature rating of the system.
Provide power from a single-phase instrument power supply. If there is a lot of
noise in the power line, insert an insulating transformer into the primary side of
the line and use a line filter on the secondary side. Do not place the primary
and secondary power cables close to each other.
For thermocouple input, use shielded compensating lead wires for wiring. For
RTD input, use shielded wires that have low conductor resistance and cause no
significant differences in resistance between the three wires. Do not connect
Terminal
– 23
when thermocouple or Linear input is selected.
Use repeater after each set of 32 instruments connected in RS-485
Communication.
Unused terminals shouldnot be used as jumper points asthey may be internally
connected, which may cause damage to the unit.
CAUTION:
High voltage transients may occur when switching inductive loads such as some
contactors or solenoid valves. Through the internal contacts, these transients may
introduce disturbances which could affect the performance of the instrument.
For this type of load it is highly recommended that a “snubber” is connected across the
normally open contact of the relay switching through load. The snubber recommended
consists of a series connected resistor/capacitor (typically 15nF/100Ohms). A snubber
will also prolong the life of the relay contacts. A snubber should also be connected
across the output of a triac output to prevent false triggering under line transient
conditions.
