Lennox EIM - Page 18

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Table 1. Alert Codes and Troubleshooting
GF= Gas Furnace, AH=Air Handler, ID=Indoor unit (GF or AH), HP=Heat Pump, AC=Air Conditioner, OD=Outdoor Unit (AC or HP), PA=Pure Air S, ZA=Zone system and
TS=Thermostat
Alert
Code
Priority
Condition
Actual Displayed
Alert Text
Under dealer
control center >
Notications
Component or System Operational State and Troubleshooting Tip
How to clear
alert code
114
Service
Soon/Service
Urgent
AC Line
Frequency /
Distortion Prob
In most cases the errors will have something to do with the transformer(s) phasing, input power or output loading (amperage load).
For the air handler control only, alert code 114 is generated only if the measured line frequency is below 57Hz or above 63Hz and remains
out of range for 10 consecutive seconds. We count power line cycles and determine line frequency every 1 second of time based on the
processor’s quartz crystal oscillator. We have a fair amount of ltering on when we consider a power line cycle to have occurred, so there
would have to be really bad distortion for it to count an extra cycle or miss a real cycle.
Voltage low enough to miss a cycle would generate an alert code 115. There are lots of events, such as power utility substation switching, that
could occasionally make our power line frequency o󰀨 by one count. These are rare one-time events and I don’t know anything other than a
generator with bad frequency that could cause problems long enough to cause this alert code.
There is a frequency / distortion problem with the power to a specic system component. This alert code may indicate transformer
overloading.
Check the voltage and line power frequency.
Check the generator operating frequency, if the system is running on back-up power.
Correct voltage and frequency problems.
System will resume normal operation ve seconds after fault recovered.
All applicable system component outputs are disabled – moderate condition.
After 10 minutes, the priority condition is escalated – critical condition.
Damper control module will operate in central mode only until proper voltage is restored or frequency distortion is resolved – moderate condition.
If connected to iHarmony, set damper control module transformer jumper to system transformer. Check for proper wiring. Replace 40VAC
furnace transformer with 70VAC transformer. Re-commission system.
NOTE: The unitary control (outdoor unit control board) whether it is a single, two-stage or multi-stage control is not displaying alert code 114.
115 Service Soon
Low Secondary
(24VAC) Voltage
24VAC power to a system component control is lower than the required range of 18 to 30VAC.
Check and correct voltage.
Check for additional power-robbing system components (devices) connected to system.
This alert code may require the installation of an additional or larger VA transformer.
Damper control module will operate in non-zone mode until proper voltage is restored.
Automatically clears when
the system detects the
issue no longer exists.