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➤ The coolant should be mixed in the proportions specified by the manufacturer.
Coolant mixture table:
Percentages [% vol.]
Frost protection up to approx. [°F]
Corrosion inhibitor/anti‐
freeze
Water
50
50
−34.6
Tab. 97 Coolant mixture table
Do not use a higher concentration than 55% vol. of anti-corrosion agent/antifreeze, even at
extremely low ambient temperatures. Maximum frost protection is achieved with 55% vol. of
anti-corrosion agent/antifreeze. This corresponds to frost protection down to approx. −49°F.
The concentration of antifreeze should not be less than 33%, since corrosion protection can
no longer be guaranteed and heat transfer properties deteriorate beyond this point!
10.4.1.4 Filling/refilling the coolant
In order to ensure optimum frost/corrosion protection and prevent the build-up of deposits (sludge)
in the cooling circuit, the proportion of antifreeze in the coolant should not be permitted to fall below
33%. Replenishing solely with water dilutes the antifreeze concentration and is therefore prohibi‐
ted.
Ensure that there is sufficient space for the coolant to expand without overflowing when hot.
Precondition The «battery isolating switch» is turned off.
1. Twist and remove the coolant expansion tank filler cap.
2. Mix a quantity of coolant according to the table and replenish to the mark.
Replenish the coolant just below the
maximum mark
A
.
3. Screw on the filler cap.
4. Turn on the «battery isolating switch».
5. Close the door.
6. Start the engine and allow to IDLE for about 1 minute.
7. Stop the engine.
8. Open the right-hand access door.
9. Check the coolant level.
If the coolant level in the expansion tank has decreased: Replenish the coolant.
10. Visually inspect for leaks.
11. Close the door.
10.4.1.5 Draining the coolant
Precondition The machine has cooled down.
The «battery isolating switch» is turned off.
10 Maintenance
10.4 Drive engine maintenance
122
Operator Manual Portable Rotary Screw Compressor
MOBILAIR M82 SIGMA CONTROL SMART
No.: 901783 08 USE