Troubleshooting

Self-Diagnostic Tests

The LTMR controller performs self-diagnostic tests at power-up and during operation. These tests, the errors they detect, and the steps to take in response to a problem are described below:

Type	Detected Error	Action
Major internal trips	Internal temperature trip	This trip indicates an alarm at 80°C, a minor trip at 85°C, and a major trip at 100°C. Take steps to reduce ambient temperature, including: Add an auxiliary cooling fan Remount the LTMR controller and expansion module to provide more surrounding free space. If the condition persists: 1 Cycle power. 2 Wait 30 s. 3 If the trip persists, replace the LTMR controller.
	CPU detected failure	These trips indicate a hardware detected failure. Take the following steps: 1 Cycle power. 2 Wait 30 s. 3 If the trip persists, replace the LTMR controller.
	Program checksum trip
	RAM test trip
	Stack overflow
	Stack underflow
	Watchdog timeout
Minor internal trips	Invalid configuration trip	Indicates either a bad checksum (Config checksum trip) or good checksum but bad data (Invalid config trip). Both caused by hardware detected failure. Take the following steps: 1 Cycle power and wait 30 s. 2 Reset the configuration settings to factory settings. 3 If the trip persists, replace the LTMR controller.
	Configuration checksum (EEROM) trip
	Internal network communications detected failure	These trips indicate a hardware detected failure. Take the following steps: 1 Cycle power and wait 30 s. 2 If the trip persists, replace the LTMR controller.
	A/D out of range trip
Diagnostic detected errors	Start command check	Indicates that the device has detected the presence or absence of motor current contrary to the expected state. Check the following: Relay outputs All wiring, including: Control wiring circuit, including all electromechanical devices Power wiring circuit, including all components Load CT wiring. After all checks are complete: 1 Reset the trip. 2 If the trip persists, cycle power and wait 30 s. 3 If the trip persists, replace the LTMR controller.
	Stop command check
	Stop check back
	Run check back
Wiring/config trips	CT reversal trip	Correct the polarity of the CTs. Be sure that: All external CTs face the same direction All load CT wiring passes through windows in the same direction After the check is complete: 1 Perform a trip reset. 2 If the trip persists, cycle power and wait 30 s. 3 If the trip still persists, replace the LTMR controller.
	Current/Voltage phase reversal trip	Check: L1, L2 and L3 wiring connection to be sure wires are not crossed Motor Phases Sequence parameter setting (ABC versus ACB) After all checks are complete: 1 Perform a trip reset. 2 If the trip persists, cycle power and wait 30 s. 3 If the trip persists, replace the LTMR controller.
	Phase configuration trip
	PTC connection trip	Check for: Short circuit or open circuit in the motor temp sensor wiring Wrong type of motor temp sensing device Improper configuration of parameters for selected device. After all checks are complete: 1 Perform a trip reset. 2 If the trip persists, cycle power and wait 30 s. 3 If the trip persists, replace the LTMR controller.
	Voltage phase loss trip	Check for: Improper wiring, such as loose terminations Blown fuse Cut wire Single-phase motor configured for 3-phase operation Failure to wire a single phase motor through both A and C load CT windows Loss of power source (for example, utility power failure). After all checks are complete: 1 Perform trip reset. 2 If the trip persists, cycle power and wait 30 s. 3 If the trip persists, replace the LTMR controller.