Why did my Ingersoll Rand compressor trip on motor overload?
Short answer: Main or fan motor overload contact opened. If your Ingersoll Rand SSR Intellisys (SG-era controller) is showing MOTOR OVERLOAD / FAN MOTOR OVERLOAD, the controller has logged a specific, documented condition. This page covers what it means, what causes it, what you can safely fix yourself, and when — and why — it takes a technician.
What exactly is the machine telling you?
The main motor or fan motor overload contact opened for more than one second, indicating excess current draw, and the controller tripped the unit.
Which machines show this?
larger Ingersoll Rand SSR rotary screw packages carrying the SG-generation Intellisys controller, which dropped numbered messages in favor of plain-English fault text — CHECK INLET CONTROL, LOW UNLOADED SUMP, HIGH SUMP PRESSURE, CHECK MOTOR ROTATION and the like — on the display. These machines use a stepper-driven inlet valve and a pressure transducer on the sump, and several of the faults exist purely to protect the airend from conditions like reverse rotation or lost lubricant circulation. Practical tip: treat CHECK MOTOR ROTATION as a stop-everything alarm — it almost always follows electrical work that swapped two phases, and running a screw airend backwards destroys it in minutes.
What causes it?
- Main or fan motor drawing excess current for over a second
- Blocked fan or dirty cooler airflow paths loading the motors
- Ambient temperature beyond the unit's rating
- An electrical or mechanical fault if the trip repeats
Can you fix it yourself?
Sometimes — cool-down, airflow cleanup, and one reset is the in-house scope. A second trip means stop resetting and make the call.
Step by step — what to try, in order:
- Allow the motor and starter to cool before resetting
- Check that the fan and cooler airflow paths are clean and unblocked
- Verify ambient temperature is within the unit's rating
- Reset once and note if the trip repeats
When do you need a technician — and why?
The starter enclosure carries line voltage, and finding why a motor pulls excess current takes an ammeter and mechanical checks — electrician or compressor technician work.
If it does come to a service call and you're in Nashville, TN or Birmingham, AL, we maintain independently compiled lists of local companies that service industrial air compressors — real businesses with verified contact information, none of whom paid to be listed.
Related questions
What does MOTOR OVERLOAD / FAN MOTOR OVERLOAD mean on an Ingersoll Rand SSR Intellisys (SG-era controller)?
Main or fan motor overload contact opened. The main motor or fan motor overload contact opened for more than one second, indicating excess current draw, and the controller tripped the unit.
Can I fix MOTOR OVERLOAD / FAN MOTOR OVERLOAD on an Ingersoll Rand SSR Intellisys (SG-era controller) myself?
Sometimes — cool-down, airflow cleanup, and one reset is the in-house scope. A second trip means stop resetting and make the call.
When does MOTOR OVERLOAD / FAN MOTOR OVERLOAD on an Ingersoll Rand SSR Intellisys (SG-era controller) need a technician?
The starter enclosure carries line voltage, and finding why a motor pulls excess current takes an ammeter and mechanical checks — electrician or compressor technician work. A repeating overload means an electrical or mechanical problem — call a qualified electrician or compressor technician; do not bypass or repeatedly reset it.
Verified against service documentation: Ingersoll Rand SSR Intellisys (SG-era controller) documentation for MOTOR OVERLOAD / FAN MOTOR OVERLOAD (manualslib.com)