48/50PG and PM
Space Humidity Sensor
The space relative humidity sensor (part no. 33ZCSENDRH−01 duct mount or 33ZCSENSRH−01 wall mount) is a field−installed accessory. The space relative humidity (RHS) may be selected for use if the outdoor air quality sensor (OAQ) is not used and an economizer board is installed. When installing the relative humidity sensor, the unit must be configured by setting Configuration→UNIT→RH.S to YES.
TB−1 . . . . . . . . . . 24 VDC Loop Power
TB−4 . . . . . . . . . . 4−20mA Input Signal
SERVICE
!WARNING
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could cause personal injury or death.
Before performing service or maintenance operations on unit, turn off main power switch to unit and install lockout tag. Ensure electrical service to rooftop unit agrees with voltage and amperage listed on the unit rating plate.
!WARNING
UNIT OPERATION AND SAFETY HAZARD
Failure to follow this warning could cause personal injury, death and/or equipment damage.
Puronr (R−410A) refrigerant systems operate at higher pressures than standard R−22 systems. Do not use R−22 service equipment or components on Puron refrigerant equipment.
!WARNING
FIRE, EXPLOSION HAZARD
Failure to follow this warning could result in personal injury, death and/or property damage.
1. Improper installation, adjustment, alteration, service, or maintenance can cause property damage, personal injury, or loss of life. Refer to the User’s Information Manual provided with this unit for more details.
2.Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other
appliance.
What to do if you smell gas:
1.DO NOT try to light any appliance.
2.DO NOT touch any electrical switch, or use any phone in your building.
3.IMMEDIATELY call your gas supplier from a
neighbor’s phone. Follow the gas supplier’s instructions.
4.If you cannot reach your gas supplier, call the fire department.
!WARNING
FIRE, EXPLOSION HAZARD
Failure to follow this warning could result in personal injury or death.
Disconnect gas piping from unit when pressure testing at pressure greater than 0.5 psig. Pressures greater than
0.5psig will cause gas valve damage resulting in hazardous condition. If gas valve is subjected to pressure greater than
0.5psig, it must be replaced before use. When pressure testing
Cleaning
Inspect unit interior at beginning of each heating and cooling season and as operating conditions require. Remove unit top panel and/or side panels for access to unit interior.
Coil Maintenance and Cleaning Recommendation
Routine cleaning of coil surfaces is essential to maintain proper operation of the unit. Elimination of contamination and removal of harmful residues will greatly increase the life of the coil and extend the life of the unit. The following maintenance and cleaning procedures are recommended as part of the routine maintenance activities to extend the life of the coil.
Remove Surface Loaded Fibers
Surface loaded fibers or dirt should be removed with a vacuum cleaner. If a vacuum cleaner is not available, a soft
NOTE: Use of a water stream, such as a garden hose, against a surface loaded coil will drive the fibers and dirt into the coil. This will make cleaning efforts more difficult. Surface loaded fibers must be completely removed prior to using low velocity clean water rinse.
Periodic Clean Water Rinse
A periodic clean water rinse is very beneficial for coils that are applied in coastal or industrial environments. However, it is very important that the water rinse is made with very low velocity water stream to avoid damaging the fin edges. Monthly cleaning as described below is recommended.
Routine Cleaning of NOVATION Heat Exchanger Coil Surfaces
To clean the NOVATION Heat Exchanger condenser coil, chemicals are NOT to be used; only water is approved as the cleaning solution. Only clean portable water is authorized for cleaning NOVATION Heat Exchanger condensers. Carefully remove any foreign objects or debris attached to the coil face or trapped within the mounting frame and brackets. Using a high pressure water sprayer, purge any soap or industrial cleaners from hose and/or dilution tank prior to wetting the coil.
Clean condenser face by spraying the coil core steadily and uniformly from top to bottom directing the spray straight into or toward the coil face. Do not exceed 900 psig or a 45 degree angle; nozzle must be at least 12” (30 cm) from the coil face. Reduce pressure and use caution to prevent damage to air centers (fins). Do not fracture the braze between air centers and refrigerant tubes. Allow water to drain from the coil core and check for refrigerant leaks prior to startup.
82
