Issue:
Dirty Filter
Resolution:
This diagnostic occurs if the dirty filter switch is closed. All IntelliPak units ship with a dirty filter switch as standard. It is located between the economizer dampers and the filters on the service access side of the unit. This is a differential pressure switch that measures the pressure drop across the filters. The switch should be field adjusted at unit startup to close at clean filter pressure drop + 0.5 IWC. This is an information only diagnostic. No unit functions will be disabled because of this diagnostic. Turn the dial CW to increase the setting. The adjustment is approximately 0.5" WC per 1/2 turn.
Items to check include:
- filters
- unit wiring
- switch operation
- control module
Here are the steps for Intellipak Rooftop
Step #1 Filters
Check the status of the filter in the unit. Replace if excessively dirty. If not, proceed to the next step.
Step #2 Wiring Error
Verify the wiring between the Dirty Filter Switch and the Rooftop Module (RTM, 1U48) J7-9 and J7-10. Refer to unit schematics for wire numbers and connections. If the wiring checks good, proceed to the next step.
Step #3 Switch Checkout
Verify switch is installed and pneumatic tubing is properly connected. With an ohmmeter, verify switch closes when pressure rises on the HIGH port. If the switch functions properly, proceed to the next step.
Note: This is an adjustable switch, so there are no specific make/break points.
Step #4 Control Module
Remove the wiring on pins J7-9 and J7-10 on the RTM (1U48). Reset the diagnostic and restart the unit. If the diagnostic returns, replace the RTM. If it does not, recheck the wiring and the switch.
Notes:
The filter switch is a standard feature on the IntelliPak units
WARNING:
Information in this article is intended for use by individuals possessing adequate backgrounds of electrical and mechanical experience and who comply with all federal, state, and local laws, rules, orders, or regulations related to the installation, service, or repair of a heating or central air conditioning product. Any attempt to install, service, or repair a heating or central air conditioning product may result in personal injury and/or property damage. The manufacturer or seller cannot be responsible for the interpretation of the information contained herein, nor can it assume any liability in connection with its use.