Electrical Connection; General Instructions - HBM TTS Mounting Instructions

Electrical connection

6 Electrical connection
16
6.1

General instructions

Electric and magnetic fields often cause interference
voltages in the measuring circuit. This interference
comes primarily from power lines lying parallel to the
measuring leads, but it can also come from nearby
contactors or electric motors. Interference voltage can
also be coupled galvanically, especially by grounding the
measurement chain at a number of points.
Please follow the below instructions:
S Use only shielded and low‐capacitance measurement
cables for six wire circuit from HBM.
S Do not position the measurement cables parallel to
power lines or control circuits. If this is not possible
(e.g. in cable shafts), protect the measurement cable
with armoured steel tubing, for example and keep it a
minimum distance of 50cm away from the other
cables. Power lines or control circuits should be
twisted together (15 twists per meter).
S Guard against stray fields from transformers, motors
and contactors.
S Do not ground the transducer, the amplifier and the
indicator more than once. All the measurement chain
devices must be connected to the same grounded
conductor.
Grounding concept (Greenline)
The cable shield of the connection cable is connected to
the measuring head of the transducer. This encloses the
measurement system in a Faraday cage. Any electro­
A1571-3.0 HBM: public
TTS