
➤ The coolant should be mixed in the ratio specified by the manufacturer.
Coolant mixture table:
Percentages [% vol.]
Frost protection down to ap‐
prox. [°F]
Anti-corrosion agent/anti‐
freeze
Water
50
50
−35
Tab. 74 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
The percentage of antifreeze in the coolant should not fall below 33%, so as to ensure optimal frost
and corrosion protection and prevent the build-up of deposits (sludge) in the cooling circuit. Re‐
plenishing solely with water dilutes the antifreeze concentration and is therefore prohibited.
Ensure that there is sufficient space for the coolant to expand without overflowing when hot.
Precondition The «Controller ON/OFF» switch is switched off,
the negative cable of the battery has been disconnected.
1. Loosen and remove the coolant expansion tank filler cap.
2. Mix a quantity of coolant as per the table and replenish to the level indicated.
Replenish the coolant to just below the
maximum mark
A
.
3. Install lid.
4. Connect the negative cable to the battery.
5. Switch on the «Controller ON/OFF» switch.
6. Close the door.
7. Start the engine and allow to run in IDLE for about 1 minute.
8. Stop the engine.
9. Open the left-hand door.
10. Check the coolant level.
If the coolant level in the coolant expansion tank has decreased: Replenish the coolant.
11. Visually inspect for leaks.
12. Close the door.
10.4.1.5 Draining the coolant
Precondition The machine has cooled down.
Both doors are open.
The «Controller ON/OFF» switch is switched off,
the negative cable of the battery has been disconnected.
10 Maintenance
10.4 Drive engine maintenance
No.: 902366 10 USE
Operator Manual Portable Rotary Screw Compressor
MOBILAIR M55 PE SIGMA CONTROL SMART pV
103