4.4.3 Replacing LVDT
1. Remove power from the unit.
2. Remove the transmitter housing cover.
To remove old LVDT:
3. Locate the black wire which runs from the top of the
LVDT to the lower right hand corner of the transmitter
PC board. Remove the eight pin connector on this wire
from J1 on the transmitter PC board.
4. Remove the c-ring above the LVDT on the enclosing tube
using a snap ring pliers.
5. Carefully slide the LVDT from the enclosing tube. If
necessary, clip the plastic tie wrap on the transmitter
PC board.
6. Install new LVDT by reversing the above steps.
4.4.4 Checking the LVDT Winding Resistance
Refer to Figure 26 during this procedure.
1. Remove power from the unit.
2. Remove the transmitter housing cover.
3. Locate the black wire which runs from the top of the
LVDT to the lower right hand corner of the transmitter
PC board. Remove the eight pin connector on this wire
from J1 on the PC board.
4. Using a multimeter, check the primary winding by verify-
ing that pins 2 and 6 of the eight pin connector have
approximately 78 to 117 ohms resistance.
5. Check the secondary winding by verifying that pins 1 and
5 or pins 4 and 8 of the eight pin connector have approxi-
mately 72 to 109 ohms resistance.
6. If the winding resistance is out of range, replace LVDT.
4.5
Maintenance of Digital ES II Modulevel
4.5.1 Replacing Transmitter PC Board
Refer to Figure 27 during this procedure.
1. Remove power from the unit.
2. Remove transmitter housing cover.
To remove old board:
3. Remove two screws which secure the PC board bracket to
the housing base.
4. Remove two wires from TB1 on the PC board.
29
48-618 ES/EZ Modulevel Displacer Level Transmitter (Top Hat Assembly Design)
Figure 26
LVDT Eight Pin Connector
1 2 3
4
7
8
6 5
7
8
6 5
