Varec 7532, Installation And Operation Manual

Page: 30 / 106

Wiring Radar Tank Gauge
30 Installation and Operations Manual
4.3 Equipotential bonding
Connect the Equipotential bonding to the external ground terminal of the transmitter.
Caution!
In Ex applications, the instrument must only be grounded on the sensor side. Further
safety instructions are given in the separate documentation for applications in explosion
hazardous areas.
4.4 Degree of protection
• housing: IP 65, NEMA 4X (open housing: IP20, NEMA 1)
• antenna: IP 68 (NEMA 6P)
4.5 Overvoltage protector
• The level transmitter 7500 RTG is equipped with an internal overvoltage protector
(600 Vrms electrode). Connect the metallic housing of the 7500 RTG to the tank wall
directly with an electrically conductive lead to ensure reliable potential matching.
• Installation with additional overvoltage protector HAW 262 Z (see XA 081F-A
"Safety instructions for electrical apparatus certified for use in explosion-hazardous
areas").
–Connect the external overvoltage protector and the 7500 RTG transmitter to the local
potential matching system.
–Potentials shall be equalised both inside and outside the explosion hazardous area.
–The cable connecting the overvoltage protector and the 7500 RTG transmitter shall
not exceed 1 m in length;
–The cable shall be protected e.g. routed in an armoured hose.
4.6 Post-connection check
After wiring the measuring instrument, perform the following checks:
• Is the terminal allocation correct (see page 25)?
• Is the cable gland tight?
• Is the housing cover screwed tight?
• If auxiliary power is available:
Is the instrument ready for operation and does the liquid crystal display show any
value?