Caution!
The CPT 1/A transmitter should be connected only after the supply voltage has been checked. The transmitter outlets should not
be connected to the actuator frame, neither should they be earthed, even accidentally.
1)
Before the supply voltage is checked the transmitter should be disconnected from the AC mains. At the actuator terminals
to which the transmitter is connected, the voltage can be best measured by a digital voltmeter withan input resistance of
at least 1 Mohm. This voltage should be within the range of 18 to 25 Vdc, but should not exceed 30 V since otherwise
the transmitter might be damaged. Then, connect the transmitter so that the positive terminal of the power supply is
connected to the „plus“ pole of the transmitter, i.e., to the pin provided with a red insulator (r)+ (nearer to the transmitter
centre), and the terminal with a white coating (extended to terminal -52- or H) to the „minus“ pole of the transmitter (white
insulator). In the la-test design variant, the red conductor is „plus“ and the black conductor is „minus“.
2)
Connect temporarily a milliammeter, preferentially a digital instrument with an accuracy of at least 0.5% in series with
the transmitter. Bring the output shaft into the CLOSE position. In this case, the signal value should decrease. If this is not
the case, turn the output shaft in the CLOSE direction till the signal starts decreasing and the output shaft reaches
the CLOSE position.
Then, loosen the screws of the transmitter shim plates so that the whole transmitter can be turned to set a current
of 4 mA. Retighten the screws of the transmitter shims. Subsequently, adjust the actuator output shaft to the OPEN
position. Set the current to 20 mA by the trimming resistor fitted on the transmitter face (nearer to the edge).
The trimmer has 12 turns, but no stops. Thus, it cannot be damaged.
If a considerable correction of 20 mA current is required the 4 mA and 20 mA setting procedure should be repeated.
Then, disconnect the milliammeter. Avoid turning the screw situated nearer to the middle and secured by a dropof
varnish. Retighten the fixing screws of the transmitter shim plates and secured them with a drop of varnish.
On completion of the adjusting procedure, check the terminal voltage of the transmitter by a voltmeter. This voltage
should be within the range of 9 to 16 V with 20 mA current.
Note:
The transmitter characteristic has two branches: A descending one and an ascending one with respect to
the CLOSE position (Z).
Setting of current position transmitter CPT1.
Before starting setting the current transmitter it is necessary to set the end-limit positions (torque or position switches) of
the actuator and connect them into the tripping circuit of the electric motor. In case of an external source of feeding voltage,
verification must be carried out that it does not exceed the maximum value 30 V DC (limit value when CPT1 is still not
damaged). Recommended value is 18 – 28 V DC.
Positive pole of the source is connected to the positive pole of the
transmitter CPT1; a milli-ammeter of precision at least 0.5 % connected into
the circuit. The current loop must be earthed in one point. The figure does not
show the earthing that can be made at any point of the circuit.
1.
Shift the output shaft into the position Closed. During closing, the current
signal value should decrease. If it increases release the transmitter body
and, by turning of about 180°, shift to the descending part of the
outputcharacteristics. Set 4 mA by fine turning. Tighten the shim plates to
secure the transmitter against spontaneousturning.
2.
Shift the output shaft to the position Open and set 20 mA using a potentio-
meter on the transmitter body. The potentiometer has a range of 12 revo-
lutions and it has no stops so that it cannot be damaged by furtherturning.
3.
Once again verify the current value in the position Closed. If it has changed
too much repeat the points 1. and 2. If the required corrections are large this procedure should be repeated several times.
After the setting, securethe transmitter against turning and drip the screws with varnish.
4.
Use a voltmeter to check the voltage on the CPT1 terminals. In order to keep linearity of the output signal
the voltage must not drop below 9 V, not even with off-take 20 mA. If this condition is not met it is necessary to increase
the feeding voltage (within the range of recommend values) or to decrease total resistance of the current loop R.
Setting of current position transmitter DCPT.
1. Set of end-limit positions
Before starting the setting, verification must be carried out that the end-limit positions are within the range
60° – 340° of revolution DCPT. Otherwise, after setting, an error arises (LED 2x).
1.1. Position “4 mA”
Set the drive into the required position and press the push-button
“4”
until LED blinks (about 2 s).
12
Summary of Contents for MODACT MON 100/130-100
Page 2: ......
