On a group 9 actuator (MAR 10, 50, 90) make sure the manual override has not already been used. If the manual override has been used, the knob will be 5/16 higher when the geartrain is disconnected.

If this is the cause of the issue, the run time will be no longer than twice the run time (e.g., 10 second actuator will run for 20 seconds). Then the gear train aligns itself and the manual override will automatically lower and re-engage.

If you attempt to help it by hammering on the override shaft, it will be damaged and must be sent back for repair.

The other possibility that goes for all MAR models is a broken gear. Then the actuator must be sent back for repair.

Power to the clutch coil must be present to engage the gear train with the output shaft. If power is present, then there is damage to the clutch assembly and must be sent in for repair.

Make sure the fail position cam is engaged properly when no power is applied. If the hard stop was adjusted but the fail position cam was not, then most likely it is attempting to drive to fail and is just spinning in the clutch bearing.

If the actuator is in the mid position or is spinning both directions, then there is most likely a broken gear and the actuator must be sent it for repair.

With a KTBRAK1SSQ brake on a SUREPOWR the hub and brake disc sit son top, so when there is no power to it you should see a gap between the disc and the coil. The tolerance for that gap is 0.011 to 0.013 of an inch. If there is no gap it will create drag on the motor while causing unnecessary wear to the brake. To adjust it you will need a 0.050 allen wrench. With a feeler gauge set the gap, then tighten the set screws.

With a MRBRAK1CSQ brake that has the lever and black plastic wheel you will want to check the clearance by pulling back the plunger in the coil by hand, it is very easy, and check to make sure there is a gap by turning the wheel while observing the gap. Then releasing the lever and verify resistance by turning the wheel by hand. This is still easy, but you should feel a difference. The coil is mounted with slotted holes and the bracket that holds the lever arm can be adjusted with pliers.

With a KTBRK88-625-1 brake that has the coil on top and has a fiber brake disk, you need to adjust the clearance of the hex hub on the motor rotor and the bottom of the coil. While there is no way to effectively check the gap, you can adjust it to prevent any interference.

This is done by removing the coil mounted with the four 1/4 head screws that also bolt down the motor. Take care not to let the motor come apart during this process. You will probably notice there is a little up and down movement of the motor rotor, and that is what you will want to minimize. The flat hex hub is secured to the rotor by two set screws use a 5/64 or a 2mm allen wrench to loosen them. Now without pulling the motor apart, pull up on the rotor while letting the brake hub sit on the top of the bell housing. No force is needed otherwise you will bind the rotor.

Retighten the set screws and verify the rotor spins freely. Reassemble the motor and brake making sure the hub fits back into the brake disk and that the brake mounting bracket sits flush to the top of the motor at all four corners. Install the motor and brake with the four hex head screws. Tighten in an X cross pattern. If possible, run the motor with the screws in but loose and do the final tightening with the motor running.

For the actuators that do not have a brake, locate and loosen the four ¼ head screws at each corner of the motor but do not remove them completely. With the motor loose check to make sure the rotor spins freely by turning it with your fingers. Re-tighten in an X cross pattern verifying the rotor remains free.

To check the brake first you should hear a click the moment the motor is energized. If you do not, you can press on the tab with two holes to manually override it and see if the motor turns. When there is no power applied to the motor you can manually override the brake, and while holding down on the tab you should be able to turn the 5/8 hex hub with your fingers. Watch out for hot surfaces from a bound-up motor.

There are three motor mount clips that hold the motor at the bottom where the housing sits on the mid plate. The housing should be siting flush all the way around. The rotor can be turned by hand without a brake or with a brake by manually overriding the brake. It does not take much of a misalignment to cause gear bind if it is in the wrong direction. This is usually an issue on startup after a newly installed actuator because of excessively rough handling. Watch out for hot surfaces from a bound-up motor.

If a motor seems weak, there is a chance that that one of the connectors on the cap may have loose connection on the motor leads or on the wires coming from the limit switches. If a connector is loose it will disconnect very easily. Watch out for shock hazard working with the capacitor always remove power when possible.

To check the brake first you should hear a click the moment the motor is energized. If you do not, you can press on the tab with two holes to manually override it and see if the motor turns. When there is no power applied to the motor you can manually override the brake, and while holding down on the tab you should be able to turn the 5/8 hex hub with your fingers. Watch out for hot surfaces from a bound-up motor.

There are three motor mount clips that hold the motor at the bottom where the housing sits on the mid plate. The housing should be siting flush all the way around. The rotor can be turned by hand without a brake or with a brake by manually overriding the brake. It does not take much of a misalignment to cause gear bind if it is in the wrong direction. This is usually an issue on startup after a newly installed actuator because of excessively rough handling. Watch out for hot surfaces from a bound-up motor.

If a motor seams weak, there is a chance that that one of the connectors on the cap may have loose connection on the motor leads or on the wires coming from the limit switches. If a connector is loose it will disconnect very easily. Watch out for shock hazard working with the capacitor always remove power when possible.

A relay is used to control power to the brake for mid position capabilities mainly in modulating applications. When the motor is energized it interrupts power to the brake allowing the motor to turn. If the brake is not releasing it may be due to a failure of the relay. Check for power to the control circuits to verify it is getting power from the motor and capacitor.

If the handwheel on a MAR 100-4000 fails to turn, there is a simple solution. With the cover off you will see a spring that connects the brake to the manual override collar. To simulate the hand wheel engagement, press down on the collar until the roll pin is above the top of the collar.

At that point, the spring should have enough tension on it to disengage the brake. To check for proper disengagement the rotor should be able to be turned with your fingers at the 5/8 hex hub. If it does not spin free the tab where the spring hooks can be adjusted higher. Do not use any tools to turn the hub as it is easy to override the brake and makes it difficult to notice a dragging brake. And due to the gear reduction if you cannot turn the rotor with your fingers then most likely you will not be able to turn it with the hand wheel either.

There are three main reasons a MAR series actuator will oscillate. Not having a brake is the most common on an application that can back drive the actuator enough to disengage the limit switch. Another may be the valve has a mechanical hard stop and the cams set too far allowing the actuator to drive excessively into that hard stop, and in turn building tension in the bracket and gear train. The third is that the bracket could be undersized for the actuator valve combination. If you notice the actuator twisting and the mounting hardware is tight, then the bracket is storing spring tension and when it reaches the limit switch it will start to untwist till it disengages the limit switch.

A SURE 24, 25, 65, 100, 150 with power on brake that is getting proper power has two main reasons to not function properly. The easier one is an improper brake gap. The spec of the gap is 0.011 to 0.013 and any larger the brake itself may not engage when powered. The other reason is a failed brake coil so even with assistance the brake disk is not magnetically drawn to the coil.