SYSTEM ALARM — The red SYSTEM ALARM indicator signals air system or dryer operating condi- tions that may affect dew point performance or cause damage to the dryer.
The display will read the same temperature until the button is pressed again. While in this mode, the alarm set points and service due light are bypassed.
Temperature SCAN/SEEK Push Button
The SCAN/SEEK push button on the System Opera- tion Monitor provides a readout on the alphanumeric display of the following temperatures:
•inlet air
•refrigerant suction
•refrigerant discharge
•ambient air
The display can be programmed to automatically scan each temperature for five seconds in sequence or to continuously display any selected reading. The corre- sponding light on the system schematic will illuminate when the temperature is displayed.
To scan the temperatures (normal operation): press and hold the SCAN/SEEK button for three seconds. Each temperature will then be displayed for five sec- onds in the following sequence: inlet air, refrigerant suction, refrigerant discharge and ambient air. To stop the scan mode, press the TIME ADJUST button once.
To display any selected temperature (seek; test/check mode): press the SCAN/SEEK button once.
Critical Air and Refrigerant Temperatures
Table V provides the normal range for each displayed temperature when the dryers are operated in accor- dance with specified conditions. If a temperature reaches the warning set point indicated in the table, the corresponding light on the system schematic will flash during the five second display. If the temperature reaches the alarm set point indicated in the table, the System Alarm indicator will light. Refer to the Field Service Guide in this manual if any temperature read- out falls outside the normal range.
Inlet Air Temperature — If the inlet air temperature falls outside the normal range, the dryer may fail to achieve the required dew point. Check the compressor aftercooler and adjust aftercooler operation to ensure specified inlet air temperature to the dryer.
Refrigerant Suction Temperature — If the dryer has been operating for more than 20 minutes and the re- frigerant suction light flashes, there may be a malfunc- tion in the refrigeration system. Turn the dryer off and have a refrigeration mechanic identify and correct the malfunction. If the dryer is under warranty, call your local distributor for authorization before servicing.
Table V
Air and Refrigerant Temperatures
DIGITAL | THERMOCOUPLE |
| NORMAL | WARNING | ALARM SET | |
COMMENTS | TEMPERATURE | SET | ||||
DISPLAY | LOCATION | POINT | ||||
| RANGE | POINT | ||||
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| Inlet air temperature varies with |
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| changes in aftercooler cooling |
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Inlet Air | Inlet air piping | medium temperature and air | 40°F – 120°F | 100°F | 120°F | |
compressor unloading. Inlet tem- | ||||||
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| peratures higher than 100°F re- |
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| duce drying capacity. |
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Refrigerant | Refrigerant line up- | These refrigerant temperatures |
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stream of compres- | vary with the refrigeration load | 32°F – 55°F | N.A. | 25°F | ||
Suction | ||||||
sor | and are controlled by refrigera- |
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| tion valve settings. These read- |
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| Refrigerant line |
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Refrigerant | ings are used primarily by service |
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downstream of | 160°F – 240°F | N.A. | N.A. | |||
personnel to analyze refrigeration | ||||||
Discharge | ||||||
compressor |
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system performance. |
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| Outside the con- | Ambient air temperatures higher |
| > 100°F/ | > 120°F/ | |
Ambient Air | than 100°F will reduce drying ca- | 35°F – 120°F | ||||
denser | < 35°F | < 35°F | ||||
| pacity. |
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| Intermediate air temperature var- |
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| Outside surface of | ies with inlet air pressure, ambi- |
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Intermediate | ent temperature and airflow. This | Variable; see |
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chiller discharge | N.A. | N.A. | ||||
Air | reading is used primarily by serv- | Table VI | ||||
piping |
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| ice personnel to analyze refrig- |
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| eration system performance. |
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Pyramid 8000® Series Purifiers (Bulletin 289) | 7 |
