Arzel AirBoss - Master Zone Control Function; Operation with Master Control On; Bypass Operation and Remedies; Air Surging Noise

4
(1) Start with a setting of 42 deg and raise 2 deg at a time if DX Coil shows
signs of icing. Remember that it takes more than 20 min of run time to ice
up a coil. Because zoning increases the effectiveness of the a/c system it
will most likely satisfy the calling thermostat prior to icing the coil.
(2) Locate the LAT Sensor in the supply duct (not in the plenum), prior to any
trunk dampers and in a duct common to all zones. If you have to locate
the sensor in one side of a teed duct, place it in the side with the Bypass or
smallest cooling Zone.
c) To Verify Sensor calibration and LAT voltage.
i) With sensor disconnected from board, you should read approximately 11,000
– 13,000 ohms at 72 to 66 deg.
ii) With sensor disconnected from board you should read approximately 4.9 volts
DC (+/- .2 volts)
iii) With sensor connected to board, voltage should be approximately 3 volts DC
@ 70 supply air temperature.
7) MASTER ZONE CONTROL FUNCTION.
a) With the Master Zone Control switch in the “On” position.
i) Only the #1 zone will call for a system function (heat, cool or fan operation).
ii) The LED at the zone calling (other than zone #1) will illuminate but will not
illuminate the LED at the HVAC OUTPUT or the Zone Solenoid LED.
iii) All zone solenoid LED’s will illuminate and dampers will open whenever
zone #1 calls
8) Bypass Operation and Remedies
a) Air surging noise with smaller zone open.
i) Bypass most likely oversized, (Refer to Arzel Bypass Sizing Chart).
ii) Install orifice in pressure tube feeding bypass solenoid valve in panel. (Orifice
available through Arzel Zoning Technology).
iii) If bypass is proven to be too large, install a volume damper in the duct and
reduce airflow until operation is satisfactory.
b) Fan Operation Issues
i) ICM Variable speed motor is ramping up and down.
(1) Bypass is possibly oversized and/or not properly adjusted
(a) Refer to Arzel Bypass Sizing chart, add volume damper to decrease
capacity.
(b) Adjust bypass to open only when air noise exceeds tolerable levels.
(2) Blower speed is set too high for system capacity
(a) Check and adjust CFM output of blower (400 to 300 cfm / ton).
If all else Fails, Call the Arzel Tech Support Hot Line
1-800-611-8312
www.arzelzoning.com