Form O-Y, PN 273647R5, Page 2
2.0 Maintenance
Requirements
To ensure long life and satisfactory performance, a system that is operating under
normal conditions should be inspected according to the Maintenance Schedule in
Paragraph 2.1. If in an area where an unusual amount of dust or soot or other impuri-
ties are present in the air, more frequent inspection is recommended.
Refer to the illustration in
FIGURE 1
, shown on page 4 and follow the instructions in
the paragraphs referenced below to maintain this equipment. Maintenance require-
ments apply to all Models and Sizes unless noted.
1.0 General
This booklet includes operation, maintenance, and service information for Model
YDHA, Model YDMA, and Model YDSA. Before beginning any procedure, carefully
review the information, paying particular attention to the warnings. Handling of refrig-
erant should only be performed by a certified HVAC technician with knowledge of
the requirements of R-410A refrigerant and in compliance with all codes and require-
ments of authorities having jurisdiction.
There are warning labels on the unit and throughout this manual. For your safety,
comply with all warnings during installation, operation, and service of this system.
See definitions of Hazard Intensity Levels of warnings below.
Definitions of Hazard
Intensity Levels used
in this Manual
HAZARD INTENSITY LEVELS
1.
DANGER:
Failure to comply will result in severe personal injury or death
and/or property damage.
2.
WARNING:
Failure to comply could result in severe personal injury or
death and/or property damage.
3.
CAUTION:
Failure to comply could result in minor personal injury and/or
property damage.
1.0 General .......................................................2
2.0 Maintenance Requirements .....................2
2.1 Maintenance Schedule ...........................................3
2.2 Control Locations
....................................................4
2.3 Cabinet Size 1 or 2 by Model & Size Cross-Referenced
to Heat Section Size & Type
...........................5
3.0 Maintenance and Service Procedures -
Unit & Cooling Components ....................6
3.1 Filters ......................................................................6
3.2 Supply Fan and Variable Frequency Drive
.............8
3.3 Optional Dampers and Damper Actuator ................9
3.4 Condenser Fans
...................................................10
3.5 Coils and Related Cooling Components
...............10
3.6 Check Refrigerant Pressure and Temperatures
(subcooling and superheat) ...........................17
3
.7 Compressor Operation, Maint, and Replacement
19
3.8 Other Controls
.......................................................27
4.0 Maintenance/Service Procedures - Power
Exhaust and Energy Recovery ..............27
4.1 Power Exhaust, Option PE ...................................27
4.2 Energy Recovery Wheel,
Option EW .....................................................28
5.0 Maintenance/Service Procedures - Gas
Heat Section ............................................32
5.1 Gas Heat Controls
................................................32
5.2 Combustion Air and Venting
.................................37
5.3 Vent Maintenance and Operation
.........................40
5.4 Burner and Heat Exchanger .................................41
6.0 Maintenance/Service Procedures - Electric
Heat Section ............................................42
7.0 Troubleshooting ......................................43
7.1 Troubleshooting - Refrigeration ............................43
7.2 Troubleshooting Compressor Digital Controller
...45
7.3 Troubleshooting the Heat Section ........................46
INDEX .............................................................48
Table of Contents
