PCB Piezotronics IMI SENSORS 683A1 Installation And Operating Manual page 24

Metal Surround Case
The meter's plastic case is made from a fire retardant polycarbonate. A metal surround case can be ordered to
enhance the meter's fire retardant capabilities and also provide shielding against electromagnetic interference
(EMI). The metal case slides over the polycarbonate case and is held firmly in place by spring-type non-return
clips. Once the metal case has been fitted to the polycarbonate case it cannot be removed.
With the metal case in place, the meter's plastic ratchet-type mounting clips can no longer be used. A pair of
screw-type mounting clips are inserted into holes on the side of the metal case and used to mount the meter in
the panel. A ground tab on the metal case provides a ground connection between the meter's main board and the
metal case.
**Metal Surround Case must be factory installed.
PAGE 19