Zero Zone Highlight MERCHANDISER RHZC30, Руководство по установке и эксплуатации

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Installation & Operation • 15
INSTALLATION & OpERATION
Drip Time: Electric defrost does not require any drip time. Tha fans should not operate until the coil temperature is below freezing. The Zero
Zone standard case includes a fan delay thermostat that prevents the fans from operating until the coil is below freezing. Cases utilizing
electronic controls may utilize a coil temperature sensor to control fan operation instead of a fan delay thermostat.
Electric Defrost Fail-safe Times:
ICE CREAM FROZEN FOOD
RHZC30 1/day at 55 mins 1/day at 55 mins
RHZC30T 1/day at 55 mins 1/day at 55 mins
At ASHRAE test conditions and 208 volt defrost heater operation, the typical observed RHZC30 defrost durations are 55 minutes for ice cream
and 55 minutes for frozen food. At the same conditions, the typical observed RHZC30T defrost durations are 55 minutes for ice cream and 55
minutes for frozen food.
Preferred Termination: For optimal performance, Zero Zone recommends a temperature-terminated defrost, using a defrost termination
thermostat or probe sensing the coil temperature.
The RHZC30 and RHZC30T door case has the probe located in the center/bottom of the coil.
An adjustable defrost termination thermostat is an available option from Zero Zone. If the case is so equipped, the defrost termination
temperature is 50°F. Contractor should verify the 50°F setting.
Temperature termination based on coil temperature allows the length of defrost to vary depending on how much frost is on the coil and the
defrost heater voltage. Coil frost is a function of shopping patterns, stocking habits, general door maintenance, and ambient temperature and
humidity. More frost requires a longer defrost. A lower defrost heater voltage extends the defrost period.
Zero Zone electric defrost freezers are delivered with the defrost thermostat open-on-rise contacts wired in series with the defrost heaters.
Unless the installer rewires the defrost thermostat, the defrost heater is de-energized when defrosting is complete.
Zero Zone RHZC30 and RHZC30T door electric defrost freezers are also equipped with a high-limit, snap-disc thermostat that de-energizes the
defrost heater if the coil temperature exceeds 85°F to provide a secondary safety termination.
Hot Gas Defrost
Frequency: One hot gas defrost per day is recommended.
Time of day: Nighttime defrosting is preferred to avoid periods of shopping or stocking.
Drip time: Hot gas defrost requires a 5 minute drip time.
Hot Gas Defrost Fail-safe Times:
ICE CREAM FROZEN FOOD
RHZC30 / RHZC30T
Hot Gas
1/day at 30 mins
5 min drip
1/day at 30 mins
5 min drip
RHZC30 / RHZC30T
Reduced Temp Gas
1/day at 40 mins
5 min drip
1/day at 40 mins
5 min drip
Preferred Termination: For optimal performance, Zero Zone recommends a temperature-terminated defrost, using a defrost termination
thermostat or probe attached to the dump line.
At ASHRAE test conditions, termination ranges from 12-22 minutes. Measure dump line temperature, and time how long it takes to reach 65°F.
Add 5 minutes for time termination setting plus drip time.