KROHNE ALTOFLUX 2W IFM 4042K EEx-ATEX EN - Manual (Page 12)

12 ALTOFLUX 2W IFM 4042 K - EEx
7 Replacement of electronic unit
Important!
The following instructions must be followed carefully, when the IFC 040-EEx signal converter
housing has to be opened respectively closed again !
Before opening
• Make absolutely sure that there is no explosion hazard!
• If necessary provide a "Gas-free certificate"!
• Make sure that all connecting cables are safely isolated from the power supply!
When the instructions above are strictly followed, the display cover (with the glass window) can be
removed.
7.1 Removal of the electronics unit
• Raise the latch of the interlocking device by loosening the hexagon socket head cap screw
size 3, until the cover can rotate freely.
• Unscrew the cover with the special plastic wrench (black) that is supplied with the apparatus.
• Unscrew the two screws of the display unit and turn it carefully aside.
• Carefully disconnect the 12 pin connector (for field coil and electrode circuits connection) from
the electronic unit.
• Unscrew the two mounting screws of the electronics unit, which fixes the metal frame to the
back of the signal converter housing. A crosshead screwdriver type 2 Pt. Phillips is most
suitable.
• Carefully remove the electronics unit of the converter housing (see the Remark below).
Remark!
Carefully keep the connecting cables of the field coil and electrode circuits to the side of the
housing, while removing respectively inserting the electronics unit into the signal converter
housing. This is to prevent damaging of the connecting cables!
7.2 Insertion of the electronics unit
Reassemble in reverse order with the replacement of the IFC 040-EEx electronics unit:
• Insert the electronics unit in the converter housing
• Tighten the two mounting screws of the electronics unit.
• The metal frame of the IFC 040-EEx electronics unit must be securely screwed to the housing
(back-end of electronics compartment) by the two non-removable fastening screws. Screw
them with a tightening torque of 1.3 Nm.
Remark!
These two screw-connections also establish the safety-technical connection of the electronics unit
to the signal converter housing and equipotential bonding system.
• Connect the 12-pin connector
• Mount the display-unit
• Before the cover is screwed back into the housing, the screw-thread must be clean and well-
greased with an acid and resin-free grease, e.g. silicone grease.
• Screw the display cover as tight as possible into the housing by hand, so that the gasket of the
cover must be clamped to provide the required Ingress Protection (IP) degree.
• Tighten the hexagon socket head cap screw of the interlocking device.
Refer to the standard Installation and Operating Instructions for detailed information about
resetting and reprogramming the new electronics unit after replacement.