Vaisala WMT52 - Manual (Page 37)

Chapter 4 _______________________________________________________________ Installation
VAISALA_______________________________________________________________________ 35
Marine Grounding Jumper
The WMT52 should be properly grounded also in marine applications.
If it is grounded to the hull of a ship (ship’s ground) you must remove
the grounding jumper inside the WMT52. When the jumper is removed,
the signal ground is DC isolated from the chassis ground
(> 500 VDC, fulfilling the marine EMC specifications), but AC surge
currents will still be flowing, thus helping the WMT52 survive transient
overvoltages.
The jumper is located inside the sensor, on the same component board
as the screw terminals. The location of the jumper is indicated in
Figure
16 on page 35 .
0803-048 Figure 16 Grounding Jumper Location
To remove the jumper, you must open the sensor. If you need to access
the screw terminals, you should remove the jumper at the same time.
1. Loosen the three allen screws at the bottom of WMT52.
2. Pull out the bottom part of the sensor.
3. Remove the grounding jumper from the PCB.
4. Replace the bottom part and tighten the three screws. Do not
overtighten.
The following numbers refer to Figure 16 on page 35 :
1 = Grounding jumper (remove for marine applications)