2.30
Glands should be used to protect the signal cables from chafing and to ensure the
weatherproofing of the analyser. If the analyser is installed in a hazardous area these glands
should have appropriate safety approvals and be fitted to maintain the IP54 (NEMA 4)
protection.
2.11.1 Analogue Output
The analogue output board 01100 929A (or 01100 939) occupies the fourth position from the
left in the card frame. See Figure 2.12. The output is 4 to 20 mA (switchable to 0 to 20 mA or
reversed output via the keypad) for the span selected. It is not necessary to remove the card
to make connections. This board takes its own power supply from the transformer via a flying
lead connected to TB-F. Note the position of the wires in the terminal block if removing this
board.
To maintain EMC requirements, connection to TB-N and TB-E must be made using a
screened, twisted pair cable. The screen termination is made only to the 1101 (or 1102)
enclosure and the terminating wire must be maintained as short as practical (less than 40mm).
Maximum loop resistance is 600 ohms. When isolated it may be floated by 200V with respect
to the analyser.
Field connection details vary according to which analogue output board is fitted as follows.
2.11.1.1 Output With Board 01100 939
This board may be identified by having output connector, TB-N with two terminals. The top
terminal, is positive.
The output may be connected to unspecified electrical equipment, ie chart recorders or other
electrically powered apparatus.
2.11.1.2 Output With Board 01100 929A
This board may be identified by having blue output connector, TB-E with three terminals. The
bottom terminal, is an earth (ground) point which is connected to the earth (ground). The top
terminal, is positive.
The output is intrinsically safe (ib) and is not isolated. Connection may be made to one of the
following intrinsically safe indicators without the use of supplimentary zener barriers.
BEKA Associates Type BA 303B
Strainstall D 913X
MTL 633 or 634
The capacitance and inductance or inductance to resistance (L/R) ratio of the connecting cable
must not exceed the following values:
To Next Page
Loading...
Need help?
General
