WE2107
8
A2087-1.3 en/de
HBM
3
Electrical connections
3.1
Electrical installation notes
In all the housing variants, the reference ground (GND) of all the signals and
the supply voltage is connected directly to the cable shield connection in the
device, but not to the housing.
The metal housing of the WE2107M is not connected to the reference ground.
To compensate for potential differences, the metal housing of the WE2107M
must be connected to the scale structures as well as to the ground potential of
the connected devices by a low‐resistance equalizing conductor. This is unne
cessary if a potential difference of 35 V is not exceeded.
Only high‐quality, flexible cables with a shield must be used to connect the
load cells. HBM recommends using these cables for all the WE2107 connec
tions. For a connection that meets EMC requirements
(EMC = electromagnetic compatibility), the cable shield contact of all the
cables to the device ground must be low‐resistance; the shield must be
stripped to about 5 mm and the cable must be secured with the strain relief
clamps.
To minimize EMC problems, the individual wires should be as short as pos
sible from the end of the shield to the terminal. Avoid making cross‐connec
tions, such as from the interface cable to a switching input, and instead use
separate cables in accordance with the terminal arrangement. A common
cable should be used for the supply and the switching inputs.
Electrical and magnetic fields often induce interference voltages in the meas
uring circuit. Use shielded, low‐capacitance measurement cables only (HBM
measurement cables meet these conditions). Do not route the measurement
cables parallel to power lines and control circuits. If this is not possible, pro
tect the measurement cable (with steel conduits, for example). Avoid stray
fields from transformers, motors and contact switches.
Please comply with the safety instructions at the start of this description.
The load cell and all the control and supply cables are connected by means of
screw terminals inside the housing. The terminals are fitted with wire protec
tion and the use of end sleeves is recommended, particularly for the load cell
cables.
Connection terminals are identified on the motherboard by a short text or
numbers.
