Capacity Control By Using Solenoid Coils In Explosion-Proof Design; Retrofitting The Capacity Control; Start Unloading Without Capacity Control; Coupling - Bitzer OSK/N7441-EX Betriebsanleitung

5.1 Capacity control by using solenoid coils in
explosion-proof design
• Option
• ATEX marking (Ex) II 2G Ex mb IIC T4 Gb X
• For technical details, see name plate of the coil, op-
erating instructions and declaration of conformity of
the coil manufacturer.
To avoid transport damage, the explosion-proof solen-
oid coils are delivered separately as an accessory kit.
• Slide the coils onto the armature tubes and fix them.
Fig. 3: OS.(A)74 with explosion-proof solenoid coils
5.1.1

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 exactly horizontally!
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 30.
26
CR2ex CR ex 1
• Connect the cable in accordance with the schematic
wiring diagram, (see chapter Schematic wiring dia-
grams OS.(A)74.-EX, page 30).
• 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!

5.2 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.

5.3 Coupling

A coupling that may be used in an explosion-proof area
must be explicitly approved for this area by the manu-
facturer. For further information, see the name plate of
coupling, the operating instructions 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!
SB-509-3