Unit Controls
E V A P P U M P I S O N
E V A P H E A T E R I S O F F
This display indicates the status of the evaporator pump contacts and the evaporator heater.
The evaporator pump dry contacts are energized when any compressor is running, or the unit is not OFF on the daily schedule and the unit switch is on, or the unit has shutdown on a Low Leaving Chilled Liquid fault. However, even if one of above is true, the pump will not run if the micro panel has been powered up for less than 30 seconds or if the pump has run in the last 30 seconds to prevent pump motor overheating.
The evaporator heater is controlled by ambient air tem- perature. When the ambient temperature drops below 40°F the heater is turned on. When the temperature rises above 45°F the heater is turned off. An under voltage condition will keep the heater off until full voltage is re- stored to the system.
A C T I V E R E M O T E C T R L
N O N E
There are several types of remote systems that can be used to control or monitor the unit. The following mes- sages indicate the type of remote control mode active:
NONE – no remote control active. Remote monitoring may be via ISN
ISN – YorkTalk via ISN (Remote Mode)
*LOAD LIM – load limiting enabled. Can be either stage 1 or stage 2 of limiting.
*PWM TEMP –
*Refer to the section on Operating Controls
S Y S X N U M B E R O F |
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C O M P S R U N N I N G | X | |
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S Y S X | R U N T I M E |
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X X - X X - X X | - X X D - H - M - S | |
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S Y S X L L S V | I S O N |
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H O T G A S S O L I S O F F |
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S Y S X F A N | S T A G E | 3 |
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The above four message will appear sequentially, first for system 1, then for system 2.
The first message indicates the system and number of compressors that are being commanded on by the mi- cro board.
The second message indicates the system run time in days – hours – minutes – seconds. Please note that this is not accumulated run time but pertains only to the cur- rent system cycle.
The third message indicates the system, and whether the liquid line solenoid and hot gas solenoid are being commanded on by the micro board. Please note that hot gas in not available for system 2, so there is no mes- sage pertaining to the hot gas solenoid when system 2 message is displayed.
The fourth message indicates what stage of condenser fan operation is active. Unless a low ambient kit is added, only stages 1 and 2 will be used to cycle the condenser fans. However, stage 3 may be shown in this display without a low ambient kit added, but it has no effect.
See the section on Condenser Fan Control in the Unit Operation section.
68 | YORK INTERNATIONAL |
