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Electric actuator failure analysis introduction

In the electric actuator, the power fuse is often blown off or the current meter is not instructed, and the motor of the actuator does not rotate. After analysis, the reasons for this phenomenon are considered as follows.
1. The fuse is blown and the power supply meter has no indication.
1) Most of the actuators work in places with harsh environments, high dust, and easy water leakage. It is easy to deposit dust and dirt between the two pins of the power plugs 13 and 14, that is, an external "additional resistance" is formed between the two legs of the power plugs 13, 14 and the power supply is short-circuited; The fuse on the power socket causes the fuse to burn out; sometimes the outer casing of the actuator internal capacitor (such as the commutating capacitor of the actuator motor) is de-energized, and the outer casing is tightly connected to the case to form a power ground to blow the fuse.
2) The blade of the fan has a card with the outer casing, or the moving parts of the fan are rusted, or the internal transmission gear of the actuator is lack of oil, etc., which will cause the friction to increase, causing the output power of the actuator to reach the limit, due to the increase of current. Burn the fuse.
3) There is a problem inside the actuator or the transmission line. At this point, the measuring plug of the actuator can be unplugged to check if it is inside or a problem with the transmission line. If the plug is unplugged, the fuse is no longer burned out, or there is a problem inside it, otherwise it is likely that there is a problem with the transmission line. It is likely that the line near the plug is damp, causing the power leads to be shorted.
4) The plastic on the socket of the actuator deteriorates and the insulation is not good, causing a short circuit to the ground. In this case, if the actuator is removed from the instrument room, no problems will be found during the calibration. This is because there is insulation rubber on the table of the instrument room, so that it cannot be short-circuited to the ground. At the scene, if the actuator is only placed on the bracket and disconnected from the fan, the fuse is connected. If it is no longer burned, the insulation of the socket and the watch case can be measured by the shaker to judge whether the plastic on the socket is aged.
5) The power supply meter has no indication. Most of this is caused by the rectifier diode or rectifier tube inside the actuator being burned out, sometimes due to desoldering or poor contact.
2, troubleshooting and maintenance
For the 1) in the previous section, first clean the plug with alcohol. It is best to cover the actuator housing with plastic sheeting on site to prevent dust from entering the interior and preventing rainwater from splashing on the actuator. On the socket, the capacitor that is electrically charged to the outer casing and in contact with the outer casing can be wrapped with an electrical tape to insulate it from the outer casing. Of course, new capacitors can also be replaced.
For the 3) in the previous section, immediately unpack the cable or untie the signal plug wire wrapped with yellow wax cloth, find the power cable connector, and re-wrapp. If the signal line is wet or burnt, it should be cleaned before being used. If the socket plastic is aging, it should be replaced in time.
For the 4 in the previous section, check it in time and replace the damaged part.
In addition, in some occasions where the accuracy requirements are not very high, the relatively low-cost medium differential pressure transmitter can be used to replace the expensive differential pressure transmitter, saving money. But pay attention to the following two points in the actual action:
&S226; need to use high precision transmitter;
b. The actual measured liquid level range and the minimum range ratio of the selected transmitter should not be too small, so as to avoid large measurement error caused by excessive K value.

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