Commissioning method and precautions of electric door
Electrical Reading December 8, 2019
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1、 Visual inspection:
The electric valve and distribution box shall be intact, free of rust and mark, and the nameplate mark on the motor shall be clear and conform to the design. The circuit breaker, contactor and thermal relay in the distribution box shall meet the requirements of design and motor capacity. Put out the cable and connect the cable.
2、 Insulation inspection and motor inspection:
1. Insulation inspection: the motor insulation shall be greater than 0.5m Ω (500V megger is used).
2. Motor inspection: the three-phase resistance of motor coil shall be balanced (multimeter).
3、 Valve inspection:
Check whether the internal limit mechanism of the valve is damaged or rusted, and the position switch operates reliably. With the cooperation of the maintenance grinding team, check whether the valve is jammed when it is opened and closed manually.
4、 Operation loop test:
1. Carefully review the relevant drawings of the Design Institute, check and calibrate the control circuit according to the requirements of the drawings, and check whether each connecting wire is connected firmly and reliably.
2. Check whether the circuit breaker in the electric valve distribution box [drawer] meets the design requirements, and adjust the current value of the thermal relay according to the rated current of the motor.
3. Turn on the control circuit power supply (disconnect the power circuit power supply), [send the drawer to the working position], select the position switch to the local position, test whether the operation circuit acts correctly (including opening and closing the control circuit, opening and closing the lock circuit, flashing circuit, light circuit, over torque locking protection); then select the position switch to the far operation position, and operate on the DCS in the central control room (including Open and close control circuit, signal feedback circuit, over torque locking protection).
5、 Power circuit test and valve adjustment:
1. Close the power supply of control circuit and power circuit, [send the drawer to the working position], select the position switch to the local position, manually operate the valve to the middle position, and operate the open or close valve button to check whether the motor and valve are turning correctly.
2. Adjust the valve closing torque to the minimum, operate the valve closing button, close the valve to the closing torque action, walk 1-1.5 circles towards the opening direction with the cooperation of the grinding team personnel, at this time adjust the closing interruption to make it act. Then adjust the closing torque to the appropriate position according to the system where the valve is located (generally, the high-pressure system is adjusted to 7-9 position; the low-pressure system is adjusted to 5-7 position).
3. Adjust the opening torque to the minimum, operate the valve opening button, open the valve to the opening torque, and then operate it immediately. Check whether the valve stem opening and valve travel are appropriate. After the inspection is appropriate, walk 1-2 circles towards the closing direction. At this time, adjust the opening interruption to make it operate, and then adjust the opening torque to a position greater than the closing torque value 1-2.
4. Adjust the valve position to indicate the appropriate variable speed gear, so that the local position indication of the valve is consistent with the actual position of the valve.
5. If the electric valve is an adjustable valve, after the above steps are adjusted, the opening indication of the valve shall be adjusted, and the position transmitter shall be adjusted to make the opening indication displayed on the distribution box and DCS coincide with the actual position of the valve.
6. The valve shall be fully operated once, and the time of opening and closing stroke shall be recorded. Then select the position switch to "program control" position, operate once on DCS, and observe whether the indication on DCS is completely correct. Finally, run the valve to the closed position.
7. After commissioning, disconnect the power supply of control circuit and power circuit [pull out the drawer of distribution box]. Recover all parts removed from the electric head and make marks (including debugging personnel and debugging time). Set "no operation" on DCS. Put it in standby state. Keep the original records.
6、 Safe and civilized construction measures:
1. Before adjustment, it shall be confirmed that the system of the adjusted valve is in shutdown state and completely isolated from other pressure vessels. Ensure system safety.
2. Before adjustment, it shall be confirmed that there is no fitter, welder or civil construction on the upper part of the valve to be adjusted, and no one nearby is removing the scaffold.
3. Chinese signs such as "danger of electricity" shall be hung at the conspicuous place of the distribution box.
4. Before power on, each connecting wire shall be checked carefully to prevent equipment damage.
5. During power transmission, the personnel on one side of the distribution box shall notify the local personnel, and the power can be delivered only after getting the consent of the other side. Inform the other party in time after power transmission.
7、 There are two parts for the problems in the failure of electric valve
1. Water inlet in the electric valve;
The water in the electric door is mainly rain. The rain water enters the electric head from the cable trench along the cable pipe. For example, the lower header drain ා 2 electric valve at the left end, the electric head is the Omar electric valve, and if there is a fault, there is no feedback display in the picture in the central control room. It is found that the three indicator lights on the door are on at the same time on the spot. It is obvious that a fault signal is reported, which may be a torque fault. However, turning the hand wheel manually, it is found that the valve is not stuck, and the action is normal. At this time, it is speculated that the feedback device may be out of order, Open the cover to see if the feedback device is normal. At this time, I think it may be that the dial switch is not set properly or the circuit board is faulty. When the other cover is opened, it is found that there is water at the circuit board dial switch. When the power supply is cut off, wipe the water in the electric head of the circuit board dry, and work normally after power transmission.
2. In the hot state, the electric door has over torque.
In the hot state, there are many over torques in the electric valve, mainly due to the thermal expansion, the valve is stuck, and the high bypass pressure regulating valve has over torques. When the hand wheel is turned manually on the spot, it is found that the manual force is not too hard. Check that the opening torque is 700nm, and the maximum torque is 1000nm. At this time, set the opening torque as 900nm, but adjust it