Pneumatech AD Series, Owner'S Manual

10 

Service Due Indication 

“Service Due” indicates the dryer is due for routine 
maintenance. Please read the maintenance section or 
contact your Pneumatech dealer. In SERVICE DUE 
mode, several functions relating to the accumulated run 
time can be accessed. The accumulated run time can be 
viewed, and the service due threshold (total 
accumulated run time before SERVICE DUE indicator 
lights) can be viewed and tested. 
 

CAUTION 

Drains will not operate normally in Service Due 
mode. Drains will not receive power in Service Due 
mode unless the DRAIN TEST key is held down. 
Never operate the unit in Service Due mode for an 
extended period of time. 

 
To enter the SERVICE DUE mode (and view the 
accumulated run time) press SELECT, UP (

↑

) and 

DOWN (

↓

) keys simultaneously. The display will show 

the accumulated run time in tens of hours. If the display 
reads 50, for example, the accumulated run time is 500 
hours. 
 
1.  To display the service due threshold, hit the DOWN 

(

↓

) arrow key. The service due indicator will light up. 

 
2.  To test the service due timer function, push the 

SELECT and UP (

↑

) keys simultaneously. The 

accumulated run time will temporarily be set to a 
value that is 60 seconds less than the service due 
threshold setting. If the service due timer is 
functioning properly, the SERVICE DUE indicator 
will flash after the 60 seconds has elapsed. After a 
few seconds, SERVICE DUE mode will return to 
normal operation. The indicator will stop flashing and 
the accumulated run time will return to its previous 
value. 

 
3.  To reset the accumulated run time to zero, hold the 

SELECT key for 5 seconds. To exit SERVICE DUE 
mode, press the UP (

↑

) and DOWN (

↓

) keys 

simultaneously. This can not be done while a service 
due timer test is in progress. 

SHUTDOWN PROCEDURE 

1.  Open the bypass valve to allow process flow to 

continue downstream. Then close the outlet isolation 
valve on the dryer bypass piping. 

 
2.  Close the inlet isolation valve on the dryer bypass 

piping. At this time the dryer is isolated and can be 
depressurized, ready for servicing. 

 
3.  Turn the power switch to the OFF position. 
 

NOTE: 

The alarm indication light (red) signifies the 

refrigerant compressor is not running. The reasons can 
be: 
 
• Low suction pressure 
• High discharge pressure 
• Electrical problems 
• Loss of refrigerant 
• Dirty condenser 
• Leaking evaporator, etc. 
 
Refer to Troubleshooting Guide, 

Page 16

, for problem 

analysis and remedy. Call the factory if further 
assistance is required. 
 

CAUTION 

Contact factory before authorizing any warranty 
refrigeration service on the air dryer. Identify the 
dryer by model and serial numbers when calling 
factory. 

OPERATING CONDITIONS 

Entering Air Temperature 

Units are designed for entering air temperature of 100°F 
(38°C). If the temperature of entering air is to be greater 
than 100°F (38°C), the factory should be consulted to 
determine the maximum possible air flow through the 
unit. 
 

CAUTION 

The increased heat content or higher temperature air 
requires the dryer to be oversized to prevent 
overloading of the refrigerant compressor. 

Entering Air Pressure 

Standard units are designed for operating air pressure 
100 PSIG (150 PSIG MAX.). Operating below 100 PSIG 
will reduce system capacity. 
 

Ambient Air Temperature 

The allowable ambient temperature range is 40°F to 
110°F (4°C to 43°C). As temperatures approach freezing 
conditions, frost or icing may develop in the unit. At 
temperatures above 100°F (38°C), refrigeration capacity 
will decrease, therefore affecting dew point.