JPS6216082A - Operating circuit for preventing reverse rotation - Google Patents

Abstract

PURPOSE:To judge the operation or non-operation of a plugging relay simply by working an electromagnetic contactor for manually operating a motor when a power supply is antiphase-connected and the motor is not worked. CONSTITUTION:When a time limit relay 8 is operated, an electromagnetic contactor 2 for manually working a motor is conducted, thus supplying a plugging relay 10 with a power supply. When the power supply is brought to the state of a positive phase, a contact for the plugging relay 10 is closed and an electromagnetic contactor 1 for operating the motor is conducted, and the motor is operated manually. When the time passes and a time limit relay 9 is worked, conduction to the electromagnetic contactor 2 for manually operating the motor is interrupted, and an electromagnetic contactor 3 for DELTA-operating the motor is conducted. The supply of the power supply to the plugging relay 10 is also intercepted at that time. When the motor is not operated by the plugging relay 10, the non-operation of the motor is determined at a glance because a coil for the electromagnetic contactor for manually working the motor is conducted.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to an operation circuit for preventing reversal of a three-phase electric motor with human-delta starting, and particularly for determining whether a reversing prevention relay is operating or not, and providing an inexpensive reversal prevention operation circuit. The present invention relates to an operating circuit suitable for use in a relay.

[Background of the invention]

Previously, 1984 Hitachi Air Conditioner Equipment Data Book 933
As described in page 1, it is possible to detect whether the phase is positive or negative using the human-Δ starting operation, but (1)
(2) The coil of the reverse prevention relay is energized when the unit is stopped so that it can be easily determined whether the reverse prevention relay is activated and does not operate during installation, and (2) an inexpensive reverse prevention relay can be used. [Objectives of the Invention] The objects of the present invention are as follows: (1) It is possible to clearly distinguish whether the motor does not operate because the power supply is connected in reverse phase, or whether it does not operate due to some other malfunction. .

(2) An inexpensive anti-reversal relay whose coil cannot be energized all the time can be used.

The goal is to provide equipment.

[Summary of the invention]

In order to achieve the above purpose, unlike other electromagnetic contactors, electric power is not supplied to the motor even when the electromagnetic contactor operates, and the power supply is connected in reverse phase. We decided to operate this electromagnetic contactor when the electric motor is not operating. In addition, the coil of the anti-reversal relay is energized only when the electromagnetic contactor for electric secondary operation is operated, and the electromagnetic contactor for electric motor operation, which was previously energized by VC, has been energized. In the coil,
It has the feature that the current is turned on again when the reverse prevention relay operates normally.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to FIG. The operation of the time-limited relay 8 will be explained first.

First, the electromagnetic contactor 2 for electric secondary operation is energized, thereby supplying power to the reverse prevention relay 10. If the power supply is in positive phase, the contacts of this reverse prevention relay 10 close,
The electromagnetic contactor 1 for motor operation is energized, and the motor is operated manually. When the time-limiting relay 9 is activated after a further period of time has elapsed, the power to the electromagnetic contactor 2 for the electric secondary operation is cut off, and the electromagnetic contactor 3 for the motor Δ operation is energized, so that the motor is operated Δ.

Also, at this point, the supply of power to the reverse phase prevention relay 10 stops.

〔Effect of the invention〕

As explained above, according to the present invention, (1) When the electric motor is not operating, the reverse prevention relay 101C energizes the coil of the electromagnetic contactor 2 for electric secondary operation, so it can be seen at a glance.

(2) The inexpensive reverse phase prevention relay 10 whose coil cannot be energized all the time can be used without adding the auxiliary relay 7.

There is an effect like this.

[Brief explanation of the drawing]

FIG. 1 is an operating circuit diagram showing an embodiment of the present invention. 1...Magnetic contactor (for motor operation) 2...Magnetic contactor (for electric rear operation) 3...Magnetic contactor (for motor ∆ operation) 4...Protection device 5...Adjustment equipment (temperature, air volume, etc.) 6... Auxiliary relay (for self-holding) 7... Auxiliary relay (for constant energization) 8.
... Time-limited relay (for restart prevention) 9... Time-limited relay (for large-Δ operation switching) 10... Reversal prevention relay 11... Push button switch (for stop) 12...
Push button switch (for operation) 13... Fuse for operating circuit.

Claims (1)

[Claims] ■-△In the operation circuit of a three-phase motor that performs starting, the contact is closed when the supplied power is in the positive phase, and the contact is opened when the power is in the reverse phase and there is no power supply, preventing reverse rotation. In order to turn off the current to the coil of the relay, use the A contact of the electromagnetic contactor for motor operation, and place the A contact and the contact of the anti-reversal relay in parallel on the coil of the electromagnetic contactor for motor operation. , A coil of an electromagnetic contactor for motor ■ operation is arranged on the time-limited b contact side of the time-limited relay for ■-△ operation switching, and a magnetic contactor for electric motor △ operation is placed between this coil and the above-mentioned time-limited b contact. Creates a b contact, and furthermore ■-
△The coil of the electromagnetic contactor for operation is arranged on the time-limited a contact side of the time-limited relay for operation switching, and the coil of the electromagnetic contactor for operation is arranged between this coil and the above-mentioned time-limited a contact of the electric motor■b contact of the electromagnetic contactor for operation An operation circuit for preventing reverse rotation, characterized in that a contact A of a magnetic contactor for driving a motor is connected in series with the a contact point of an electromagnetic contactor for driving a motor.