Viessmann VITOCAL 151-A Installation And Service Instructions Manual page 146

Outdoor unit maintenance
Extracting the refrigerant
14. Affix a label to the outdoor unit in a clearly visible
position, containing the following information, with
date and signature:
■ Outdoor unit works with flammable refrigerant
R290 (propane).
System has been taken out of use.
■
Refrigerant has been extracted.
■
Outdoor unit contains nitrogen.
■
■ Outdoor unit may contain residual flammable
refrigerant.
Testing pressure resistance
Danger
Excessive pressure can cause damage to the
system and hazards due to high pressure and
escaping refrigerant.
Observe the permissible test pressure.
1. Connect the test device on the low pressure side
and high pressure side 1.
Or
Connect the test device on the low pressure side
and high pressure side 2.
Filling the refrigerant circuit
In comparison to non-flammable refrigerants, the fol-
lowing points must additionally be observed when
topping up flammable refrigerants:
Do not use the same fill valve for different refriger-
■
ants.
■ Position refrigerant bottles vertically.
Before commencing work, note the "Checklist for main-
tenance work" on page 136 136 onwards.
1. Check whether the safety instructions for work on
the refrigerant circuit are being adhered to: See
"Safety instructions".
2. Earth the refrigerant circuit.
3. Ensure the following conditions for filling are met:
Refrigerant circuit has been drained and evacu-
■
ated: See chapter "Extracting refrigerant".
■ Absolute pressure before filling: < 2.7 mbar
(< 270 Pa)
■ If any components were replaced, observe all
information in the separate installation instruc-
tions.
After performing any repairs (e.g. soldering/braz-
■
ing, replacing components) first carry out a pres-
sure resistance test: See chapter "Testing pres-
sure resistance".
146
(cont.)
2. Carry out a pressure test with nitrogen:
4. Fill the refrigerant circuit with R290 refrigerant (pro-
5. Close the Schrader valves so they are gas-tight. To
Test pressure: 1.43 to max. 1.44 x permissible
operating pressure
Permissible operating pressure: See chapter
"Specification".
pane) via the high pressure side 2 Schrader valve
(liquid line, see chapter "Overview of internal com-
ponents").
Danger
Oxygen in the refrigerant circuit can cause a
fire or explosion during operation.
When filling the refrigerant circuit ensure that
neither air nor oxygen gets into the refriger-
ant circuit.
Danger
An excessive refrigerant charge leads to a
risk of explosion.
Do not overfill the refrigerant circuit:
Weigh the refrigerant bottle before filling.
■
■ The refrigerant charge is equal to the
weight reduction of the refrigerant bottle.
Max. refrigerant charge: See "Specifica-
tion".
achieve this, counterhold the valve body.
Torque for dust cap union nut: 15 Nm
Torque for valve body: 0,25 Nm