Carrier 25VNA Installation Instructions Manual page 18

FINAL CHECKS
IMPORTANT: IMPORTANT: Before leaving job, be
sure to do the following:
1. Ensure that all wiring is routed away from tubing
and sheet metal edges to prevent rub-through or
wire pinching.
2. Ensure that all wiring and tubing is secure in unit
before adding panels and covers. Securely fasten
all panels and covers.
3. Tighten service valve stem caps to 1/12-turn past
finger tight.
4. Leave Users Manual with owner. Explain system
operation and periodic maintenance requirements
outlined in manual.
5. Fill out Dealer Installation Checklist and place in
customer file.
CARE AND MAINTENANCE
For continuing high performance and to minimize
possible equipment failure, periodic maintenance must be
performed on this equipment.
Frequency of maintenance may vary depending upon
geographic areas, such as coastal applications. See
Owner's Manual for information.
PURON® (R-410A) REFRIGERANT QUICK REFERENCE GUIDE
• Puron refrigerant operates at 50-70 percent higher pressures than R-22. Be sure that servicing equipment and replacement
components are designed to operate with Puron refrigerant.
• Puron refrigerant cylinders are rose colored.
• Recovery cylinder service pressure rating must be 400 psig, DOT 4BA400 or DOT BW400.
• Puron refrigerant systems should be charged with liquid refrigerant. Use a commercial type metering device in the manifold hose
when charging into suction line with compressor operating.
• Manifold sets should be 700 psig high side and 180 psig low side with 550 psig low-side retard.
• Use hoses with 700 psig service pressure rating.
• Leak detectors should be designed to detect HFC refrigerant.
• Puron refrigerant, as with other HFCs, is only compatible with POE oils.
• Vacuum pumps will not remove moisture from oil.
• Do not use liquid-line filter driers with rated working pressures less than 600 psig.
• Do not leave Puron refrigerant suction line filter driers in line longer than 72 hours.
• Do not install a suction-line filter drier in liquid-line.
• POE oils absorb moisture rapidly. Do not expose oil to atmosphere.
• POE oils may cause damage to certain plastics and roofing materials.
• Wrap all filter driers and service valves with wet cloth when brazing.
• A factory-approved liquid-line filter drier is required on every unit.
• Do NOT use an R-22 TXV.
• If indoor unit is equipped with an R-22 TXV or piston metering device, it must be changed to a hard-shutoff Puron refrigerant
TXV.
• Never open system to atmosphere while it is under a vacuum.
• When system must be opened for service, recover refrigerant, evacuate then break vacuum with dry nitrogen and replace filter
driers. Evacuate to 500 microns prior to recharging.
• Do not vent Puron refrigerant into the atmosphere.
• Do not use capillary tube coils.
• Observe all warnings, cautions, and bold text.
• All indoor coils must be installed with a hard-shutoff Puron refrigerant TXV metering device.
Copyright 2011 Carrier Corp. * 7310 W. Morris St. * Indianapolis, IN 46231 Printed in U.S.A. Edition Date: 07/11
Manufacturer reserves the right to change, at any time, specification8 and design8 without notice and without obligations,
Catalog No: 25VNA-3SI
Replaces: 25VNA- 2Sl
18