Maintenance; Repairs To The Refrigerant Circuit; Evaporator; Snow And Ice - Bosch Compress 3400i AWS Installation Manual

Maintenance

8 Maintenance
8.1

Repairs to the refrigerant circuit

The unit contains R32 refrigerant which is potentially flammable. If any
work on the refrigerant circuit is necessary, strictly follow the safety
instructions hereby given.
DANGER
Risk of electric shock!
The components in the outdoor unit conduct electricity.
The capacitor in the outdoor unit must be discharged after disconnecting
it from the power.
▶ Switch off the master switch.
▶ Wait at least five minutes before any electrical work.
DANGER
Risk of poisonous gas leakage!
The refrigerant circuit contains substances that can be transformed into
poisonous gas if they come into contact with air or open fire. Even small
concentrations of these gases can cause respiratory arrest.
▶ The room must immediately be evacuated and carefully aired out in
case of refrigerant circuit leakage.
NOTICE
Risk of deformation due to heat!
The outdoor unit insulation material (EPP) will deform if it is exposed to
high temperatures
▶ Remove as much of the insulation (EPP) as possible prior to any
soldering work.
▶ Use flame retardant cloth or wet cloth to protect the insulation
material while performing soldering work on the indoor unit.
Only a refrigerant expert can perform work on the refrigerant circuit.
▶ Only use genuine spare parts!
▶ Refer to the spare parts list when ordering spare parts.
▶ Always renew seals and O-rings removed during servicing or repair
work.
During service, the activities described below should be conducted.
Show alarms
▶ Check alarm log.
Function check
▶ Function check (indoor unit installation instructions).
Electric cabling
▶ Check the cable for mechanical damage. Exchange any damaged
cable.
Temperature sensor measured values
Please make sure that the right sensor (indoor unit installation
instructions) is used. Usage of sensors with other characteristics will
lead to problems as the controls will get the wrong temperature. Example
of problems could be personal injuries like scalding, damage of property
due to high or low temperature, low comfort is also a possible problem.
18
8.2

Evaporator

If there is dirt or dust on the outside of the evaporator or the aluminium
fins, it must be removed.
WARNING
The thin aluminium fins are fragile and can be damaged if careless.
Never wipe the delicate fins with a cloth.
▶ Hard objects may not be used.
▶ Use protective gloves to protect your hands from cuts.
▶ Do not use a too powerful water jet.
Using the wrong cleaning product may damage the installation!
▶ Do not use acid or chlorine based products since they contain
abrasives.
▶ Do not use corrosive alkaline cleaning products, e.g. sodium
hydroxide.
To clean the evaporator:
▶ Turn off the outdoor unit using the circuit breaker.
▶ Spray the fins with a liquid dish soap solution.
▶ Rinse away the soap with water.
In some regions, it is prohibited to let dish soap drain into the ground. In
such regions, if the condensation water pipe drains into a gravel bed:
▶ Remove the flexible condensation water pipe from the drain before
cleaning.
▶ Drain the dish soap into a container.
▶ Reconnect the condensation water pipe after cleaning.
8.3

Snow and ice

In some geographical regions or during periods of heavy snow, snow can
get stuck on the back and the roof of the outdoor unit. Since it leads to
icing, the snow should be removed.
▶ Carefully brush the snow off the fins.
▶ Protect the outdoor unit from snow.
8.4

Handling printed circuit boards

Printed circuit boards with control electronics are very sensitive to
electrostatic discharge (ESD). To prevent damage to the components,
special care is therefore required.
CAUTION
Damage due to electrostatic charge!
▶ Wear an ESD wrist strap when handling unenclosed PCBs.
Fig. 23 Wrist strap
The damage is not normally immediately recognisable. A PCB may
function perfectly during commissioning and problems often only arise
Compress 3400i AWS – 6721825369 (2021/11)