2 0
TRM138
To protect the input equipment of TRM138 against industrial electromagnetic interference,
the communication lines between the instrument and the transducers shall be shielded
.
Shields may be made both of special cables with braided screens, and earthed steel pipes of
suitable diameter.
Using screened cables, the maximum protection is provided by connection of their shields
to a common point in the instrument’s circuit (contacts 27, 28, 29, 42, 43, 44). However, in this case
it shall be proved that braided screens of the cables are reliably insulated from earthed metal
elements throughout the line route. If this requirement is not met for whatever reasons, the cables’
shields shall be connected to an earthed contact in the control panel.
ATTENTION!
Connection of a common point of the instrument’s circuit to earthed parts of
the facility is forbidden.
5.2.3. Instrument Connection
5.2.3.1. The instrument shall be connected by appropriate diagrams presented in
Appendix. 2
,
observing the following operations sequence.
1) Connect the instrument to the actuating units and peripherals as well as to the power source.
2) Connect the communication lines “instrument – transducers” to the primary sensing
devices.
3) Connect the communication lines “instrument – transducers” to the TRM138 inlets.
4) Install jumpers on measuring inlets not used at operation of the instrument.
ATTENTION!
1) Connection of active converters with an output signal in the form of constant
voltage (0…50 mV or 0…1 V) can be made directly to the instrument’s input
contacts, and transducers with output signal in the form of current (0…5, 0…20 or 4…20 mA) –
only after installation of an arcshunting resistor for 100 Ohm (tolerance not greater than 0.1%).
2) To protect input circuits of TRM138 against possible breakdown by static electricity
charges accumulated on the “instrumenttransducers” communication lines, before connecting
to the instrument’s terminal block their strands shall be connected to the board’s ground screw
for 1 … 2 sec.
5.2.3.2. After completion of the indicated operations the instrument is ready for use.
Onsite Installation
Section 5
Содержание TPM138
Страница 23: ...22 TRM138 Setting up Procedures Section 6 Figure 16 Programmed parameters setting diagram...
Страница 24: ...23 TRM138 Section 6 Setting up Procedures...
Страница 30: ...29 TRM138 Appendix 1 Dimensional drawing...
Страница 31: ...30 TRM138 Instrument connection Appendix 2 Figure A2 1 Instrument terminal block contacts arrangement diagram...
Страница 35: ...34 TRM138 Figure A2 10 Example of connection of various type transducers Instrument connection Appendix 2...
