Fema B Series, User Manual, Page: 8 / 36

FEMA ELECTRÓNICA . SERIES B . Models Bxx-RTU
8
1.8 To access the instrument
To open the housing, remove the screws from the back cov -
er. With each screw there is a metal washer and a plastic
washer. Once the screws are out, remove the back cover.
The figure below shows the instrument internal structure for
a B26 format. It shows the location of the 3 slots for optional
output and control modules, the power terminal and the in -
put signal terminal.
To close the instrument, place the back cover, the screws,
the metal washer and the plastic washer. The plastic washer
is in contact with the back cover. Confirm that the screws are
correctly turning inside the internal female screws.
To ensure a correct IP65 protection tighten the back cover
screws with a strength between 30 and 40 Ncm, with the
help of a dynamometer screwdriver.
1.9 Modular system
Large format meters from Series B are designed with an in -
ternal modular architecture. The output and control mod -
ules are independent and can be installed by accessing the
internal circuits of the instrument, and connecting the mod -
ule to the connection jumpers of the selected slot.
Each module is provided with a cable tie to fix the module
to the tie base. The input signal modules defines the instru -
ment function and are exchangeable, switching a tempera -
ture meter to an impulse counter only by replacing the input
signal module.
See section 2 . for information regarding the output and con -
trol options available
To install an output and control module
(1) insert the ‘module pins’ into the
‘connection jumpers’ in one of the
free slots
(2) place the ‘cable tie’ into the ‘tie
base’ and embrace the ‘module’
firmly, until it is fixed
Slot 1
Slot 2
Slot 3
Connection jumpers
Tie base
Cable tie
(1)
(2)
Module pins
Output and control module
Power
Slot for option 1
Slot for option 2
Input signal terminal
Remote keypad terminal
Slot for option 3 Back cover
Female turret
Watertight seal
Screw
Metal washer
Plastic washer
Observe precautions for handling ESD (elec -
trostatic discharge) sensitive devices
Risk of electric shock. Removing the back
cover will grant access to the internal cir -
cuits of the instrument. Operation must be
performed by qualified personnel only.