SB-509-2
21
4.1
Capacity control by using solenoid coils in
explosion-proof design
• Option
• ATEX designation (Ex) II 2G Ex mb IIC T4 Gb X
• Technical details can be found on the name plate of
the coil and in the “explosion protection” operating
instructions as well as in the declaration of conform-
ity of the coil manufacturer.
To avoid damages during transport, the explosion-proof
solenoid coils are delivered separately as an accessory
kit.
• Slide the coils onto the armature tubes and fix them.
• Connect the cable in accordance with the schematic
wiring diagrams, see chapter Schematic wiring dia-
grams OS.(A)74.-EX, page 26.
For OS.7441-EX, only one coil is required.
DANGER
Risk of explosion due to the use of non-explo-
sion-proof solenoid coils!
Only use the solenoid coils approved by
BITZER and authorised for the use in potentially
explosive atmosphere!
CR ex
1
CR2ex
Fig. 1: OS.(A)74 with explosion-proof solenoid coils
4.1.1
Retrofitting the capacity control
WARNING
The compressor is under pressure!
Serious injuries are possible.
Depressurize the compressor!
Wear safety goggles!
• Remove the blind flanges.
!
!
NOTICE
Risk of compressor damage!
Mount the solenoid coils in a way that they are
exactly vertical!
The explosion-proof solenoid coils must not be moun-
ted directly to the horizontal flanges.
• Mount intermediate flanges and armature tubes with
armature tubes aligned exactly vertical.
• Slide the coils onto the armature tubes and fix them.
• Connect the cable in accordance with the schematic
wiring diagrams, see chapter Schematic wiring dia-
grams OS.(A)74.-EX, page 26.
4.2
Start unloading without capacity control
If capacity control is not needed, the compressor may
be factory-equipped with two blind flanges including
special gaskets. This ensures an unloaded start.
4.3
Coupling
A coupling which can be used in a potentially explosive
area must be explicitly approved for this area by the
manufacturer. Further information can be found on the
name plate of coupling, in the ATEX operating instruc-
tions and the declaration of conformity of the coupling
manufacturer.
DANGER
Risk of explosion due to wear of the elastomer
elements of the coupling!
Only use a specially marked coupling which is
approved and authorised for the use in explos-
ive atmospheres!
