Baldor MN850 Section Troubleshooting, Preliminary Checks, Fault Trip Messages, Power Off Checks

Section 5

Troubleshooting

Safety Notice	Be sure to read and understand all notices, warning and caution statements in Section 1
	of this manual. If you have any questions about the safe operation of this equipment,
	please contact your Baldor representative before you proceed.
Preliminary Checks	In the event of trouble, disconnect all input power to the control and perform these
	preliminary checks.
Power Off Checks
	1.	Check all connections for tightness and signs of overheating.
	2.	Check for cracked or damaged insulators and terminal blocks.
	3.	Ensure the correct setting of the overload relay.
	4.	Check the 115VAC input power.
	5.	If one or more SCR’s should be replaced, contact Baldor.

		Table 5-1 Fault Trip Messages
	This menu is used to view the last five fault trip conditions. Additional information about
	fault trips may be found in the troubleshooting section of this manual.
	Note: The control is shipped with five fault messages in the log (P73–P77). The last
		message is “External Trip”. There is no software method to clear the fault log.
Block Title	Parameter	Description
Trips	1 16 External Trip	Use the “⇑ ” and “⇓ ” keys to scroll through the fault trip list. In this example,
		1 = the most recent trip (5 would indicate oldest). Parameters P73 to P77.
		16 = the code for the fault trip.
		External Trip = the text message for the fault trip.
		16 error conditions that cause a fault trip to occur are: (E1 – E16)
		1 – Phase loss. This is a start–up protection fault that indicates single phase power at the
		AC input. This error can also indicate phase unbalance or undervoltage (low voltage).
		2 – Too Hot. Heat sink temperature exceeded limit. Possible causes are overload, frequent
		starting, poor ventilation, excessive dirty on heat sink, high ambient temperature or high
		humidity.
		3 – SCR Signal. Excessive electrical noise on input power lines.
		4 – SCR Firing. SCR’s are not responding to firing commands. May be a result of a failed
		control board, voltage spikes on power lines, noise, loose connections or SCR failure.
		5 – SCR Signal. Excessive electrical noise on input power lines.
		6 – SCR Signal. Excessive electrical noise on input power lines.
		7 – SCR Sensing. Loss of the sensing signal from an SCR. May be a result of a failed SCR,
		loss of phase current when running, undervoltage or phase unbalance when running.
		8 – SCR Sensing. Loss of the sensing signal from an SCR. May be a result of a failed SCR,
		loss of phase current when running, undervoltage or phase unbalance when running.
		9 – SCR Sensing. Loss of the sensing signal from an SCR. May be a result of a failed SCR,
		loss of phase current when running, undervoltage or phase unbalance when running.
		10 – SCR Shorted. Shorted SCR is detected. If not using input contactor, it is recommended
		that you map this fault to an output relay to trip the circuit breaker if the error occurs. When
		one phase is shorted, motor can be stopped. However, when two or three phases are
		shorted, the motor cannot be stopped without the input contactor.
		11 – Low Current. Motor current is less than full load current level (broken belt or coupling).
		12 – C/L Timeout. Motor current exceeded current limit value. Voltage was reduced to limit
		output current but it still exceeded limit for longer than allowed.
		13 – Overload. Provides overload protection for SCR’s. (Not for motor thermal overload).
		The value of the overload current trip detection was exceeded.
		14 – Shearpin. The value of the high current Shearpin trip detection has been exceeded.
		15 – Thermistor. Optional with I/O expansion board. Refer to MN851 for information.
		16 – External Trip. Optional with I/O expansion board. Refer to MN851 for information.

MN850 Troubleshooting 5-1