Instruction manual

Wiring
28 Installation and Operations Manual
5.2.6 Current consumption
Max. 21 mA (50 mA inrush current).
5.2.7 Overvoltage protector
• The level transmitter 7500 series RTG is equipped with an internal overvoltage protector (600
Vrms surge arrester) according to EN/IEC 60079-14 or EN/IEC 60060-1 (impulse current test
8/20 μs,
Î = 10 kA, 10 pulses). Additionally, the device is protected by a galvanic insulation
of 500 Vrms between the power supply and the (HART) current output. Connect the metallic
housing of the 7500 series RTG to the tank wall or screen directly with an electrically
conductive lead to ensure reliable potential matching.
• Installation with additional overvoltage protector HAW560Z/HAW562Z (see APT226G “Safety
Instructions for electrical apparatus certified for use in explosion-hazardous areas”).
• Connect the external overvoltage protector and the 7500 series RTG transmitter to the
local potential matching system.
• Potentials shall be equalized both inside and outside the explosion hazardous area.
• The cable connecting the overvoltage protector and the 7500 series RTG transmitter
shall not exceed 1 m in length.
• The cable shall be protected e.g. routed in an armored hose.
5.2.8 Power supply
Integrated in the tank gauging system via Varec’s 4590 Tank Side Monitor (recommended
operation mode).
5.2.9 Highly accurate measurement
For highly accurate measurements the measured variable must be transmitted using the HART
protocol to ensure the necessary resolution.
5.2.10 Connection to the 4590 Tank Side Monitor
“see »Wiring with the 4590 Tank Side Monitor« on page 26“.