MZ electronic EVVA-M, Instructions For Use Manual

Page: 30 / 52

EVVA-M Rev. 01
– 2019
English
30
Electrical connection
Set the two-pole dip-switches of the sensor in the OFF position as shown in the figure:
If the switches are in a different position, you may have operating problems.
- Connect the power supply of the display instrument to pins 1 (positive) and 3 (negative) of the
connector on the back of the instrument; provide a 4A fuse as a safety element for the system
in case of short circuits or electrical problems and a battery disconnect switch to cut off power;
- The instrument supply voltage must be used to supply the sensors also via the two terminals
indicated by 10 ... 30VDC and 0V. Respect the polarity of the power supply: a possible
inversion could damage the device.
- Connect the no. 5 contact of the RS485(B-) instrument to the RS485 (B-) terminal of the first
sensor; if a second sensor is present, connect the RS485(B-) terminal of the first sensor with
the RS485 (B-) terminal of the second sensor and so on
- Connect the contact n. 8 of the RS485 (A +) instrument to the RS485 (A +) terminal of the first
sensor; if a second sensor is present, connect the RS485 (A +) terminal of the first sensor with
the RS485 (A +) terminal of the second sensor and so on.
- Connect the battery which has to be measured to the two co BATT and -BATT: this is
not the battery that powers the sensor, but the one which is measured;
- Pass the current measurement cable through the central hole of the sensor following the
direction indicated by the arrow in the drawing: if the direction of the current is reversed, the
measurement is not made correctly.
All sensors must be connected in sequence; each sensor must be connected to the
previous and next sensor (if present). Avoid making a star connection where each sensor
directly connects to the instrument: it could cause problems with data communication.