MH/T 6010-2017Constant current regulators (English PDF)

4.1 Conditions of use

4.1.1 Environmental conditions

The dimmer should be able to operate for a long time in the following environment.

a) Altitude. meet the requirements of Chapter 3;

b) Temperature. 0 °C ~ 40 °C;

c) Relative humidity. 10% to 95% (no condensation).

4.1.2 Power supply conditions

AC. 220 V±22 V or 380 V±38 V, 50 Hz±2.5 Hz.

4.1.3 Load conditions

The load is a buried single-core cable line and multiple secondary isolation transformers with lamps and other auxiliary equipment connected in series.

4.2 Electrical performance requirements

4.2.1 Basic requirements

The dimmer should be able to work normally under the conditions of use specified in 4.1, and the allowable range of output current of the dimmer at all levels is the nominal value ±0.1 A.

The dimmer suitable for the 6.6 A system should constantly output any one of the five currents specified in Table 1.

4.2.2 Constant current performance

4.2.2.1 Resistive load

Under the conditions of use specified in 4.1, when the load of the dimmer is resistive and the load is within the range of short-circuit to the rated load, each of the dimmer the level output current should meet the requirements of 4.2.1.

4.2.2.2 Inductive load

Under the conditions of use specified in 4.1, when the load of the dimmer is within the range of 50% to 100% of the rated load, the isolation of no more than 30% when the secondary of the transformer is open, the output current of each level of the dimmer should meet the requirements of 4.2.1.

4.2.2.3 Limitation and stability of output current impact

In order to reduce the current impact on the load when starting, the current should be gradually increased from zero to the selected level, but the output current is stable from starting the time at the selected level should not exceed 1 s. When switching the current level after power-on, the current output should not be interrupted and it should be switched to the selection within 0.5 s.

The fluctuation is not more than ±0.1 A within the allowable range of the current level. Regardless of power-on, power-off, current level conversion or load circuit generation when a full or partial short circuit occurs, the output current should not damage the equipment connected to the dimmer output in the load circuit or cause the dimmer to have overcurrent protection.

Protect action.

4.2.3 Efficiency, power factor and crest factor

4.2.3.1 Efficiency

When the power supply voltage is at the rated value and the dimmer outputs 5 levels of current to the resistive rated load, the dimmer with a rated capacity less than 30 kVA has an effect the rate should not be less than 0.9, and the efficiency of a dimmer with a rated capacity of 30 kVA should be no less than 0.92.

4.2.3.2 Power factor

When the power supply voltage is rated and the chopper-type dimmer outputs 5 levels of current to the resistive rated load, the power factor of the dimmer should not be less than 0.9.

When the power supply voltage is rated and the sine wave dimmer outputs 3, 4, 5 levels of current to the resistive rated load, the dimmer power factor should not be less than 0.95.

4.2.3.3 Crest factor

Under the resistive and inductive load conditions specified in 4.2.2, the crest factor of the current output by the dimmer at each light level should be less than 3.2.crest the factor is calculated according to formula (1).

4.2.4 Clearance and creepage distance

The electrical clearance and creepage distance of the dimmer (not including the step-up transformer) should meet the requirements of 8.3 in GB 7251.1-2013.

Based on this, the clearance value of B-type and C-type dimmers shall be corrected in accordance with the clearance correction coefficient in Appendix A.

The distance from the output terminal of the step-up transformer of the dimmer with a rated capacity not greater than 20 kVA to the wall of the plate cabinet shall be not less than 110 mm.

The distance from the output terminal of the step-up transformer of the dimmer with a rated capacity of not less than 25 kVA to the wall of the plate cabinet shall be not less than 140 mm.

4.2.5 Insulation requirements

4.2.5.1 Insulation resistance requirements

The insulation resistance between the main circuit of the dimmer and the casing, and between the circuits that are not electrically connected to each other, should be greater than 1 000 ohm/V.

4.2.5.2 Insulation test voltage requirements

The dimmer should be able to last for 1 min under the specified power frequency (50 Hz) insulation test voltage without breakdown or flashover.

The insulation test voltage of Type A dimmers should meet the following requirements (the insulation test voltage values of Type B and Type C dimmers shall be in accordance with the insulation test of Appendix A Check the voltage correction coefficient for correction).

a) The test voltage applied at the input end of the dimmer is selected according to its rated input voltage. For a dimmer with a rated input voltage of 220 V, for a dimmer with a test voltage of 2 000 V and a rated input voltage of 380 V, the test voltage is 2 500 V;

b) The test voltage value of the remote control interface of the dimmer is selected according to the interface type. The test voltage of the switch remote control interface is 500 V.

The test voltage of the serial remote control interface is 250 V;

c) The test voltage value of the dimmer output terminal (including transformer) is calculated according to formula (2).

4.2.6 Open circuit voltage

When the load circuit is open and the open circuit protection of the dimmer is suppressed, the effective value of the output voltage of the dimmer should not be greater than the rated value.

1.3 times the fixed output voltage.

4.2.7 Electromagnetic compatibility

4.2.7.1 Launch restrictions

When the dimmer outputs 5 levels of current to the rated resistive load under the rated input voltage, its radiated emission and conducted emission limits should comply with Table 2 and the provisions of Table 3.

4.2.7.2 Total harmonic distortion rate

When the sine wave dimmer outputs any light level current in accordance with Table 1 to the rated resistive load under the rated input voltage, its input and output the total harmonic distortion rate of the output current should not be greater than 5%.

4.3 Control

The selection of the dimmer on, off and output current level should be possible on the dimmer panel or remote control point. There should be an option on the panel A switch for controlling locally or remotely, so that the control can only be performed at the selected position. After the control position is selected, a signal should be sent to the remote control point and remain unchanged until the selection changes.

The dimmer shall be provided with an interface for receiving the on, off and selecting output current level commands issued by the remote control point and execute accordingly.

The remote control interface of the dimmer can be a switch or serial interface.

a) The standard voltage source of the switch interface should be DC 24V (or DC 48V). The power supply for the remote control can be located in the dimmer Department or external. For dimmers with switch interface, the wiring drawings and conditions of use of the interface should be provided in the product instructions;

b) The interface of the dimmer using the serial interface should meet the Modbus or CAN fieldbus standard and be provided in the product instructions the interface type, wiring drawing and communication protocol used.

4.4 Main switch

The dimmer should be equipped with a main switch, and for the dimmer equipped with a step-up transformer, the main switch should be located between the input power supply and the step-up transformer.

The switch should be able to disconnect the dimmer output under the action of the dimmer protection device, without cutting off the working power supply of the dimmer control part.

4.5 Protection measures

4.5.1 Open circuit protection

The dimmer should be equipped with an open circuit protection circuit, and the main switch should be switched and an alarm will be issued within 2 s after the load circuit is open.

Alarm sound but retain the function of alarm indication. After the open circuit fault is eliminated, you should only use the switch or button on the panel to turn off the dimmer to make the open circuit protection circuit can be restarted after reset.

4.5.2 Overcurrent protection

The dimmer should be equipped with an overcurrent protection circuit, within 5 s after the output current exceeds 5% of the highest level output current or within 1 s after exceeding 25% Cut off the main switch and issue an alarm. The dimmer should have the function of eliminating the alarm sound but retaining the alarm indication. After the overcurrent fault is eliminated, the Only use the switch or button on the panel to turn off the dimmer, so that the overcurrent protection circuit can be restarted after reset.

4.5.3 Power-down data protection

In the event of a power interruption during operation, the dimmer should automatically resume operation within 1 s after the power supply is restored, and the output current level remains unchanged.

4.5.4 Lightning protection

Lightning protection devices should be installed at the input end of the dimmer and the entrance of the signal line.

The output end of the dimmer should be provided with a lightning arrester. The arrester should be able to suppress the subsequent wake superimposed on the output line, the waveform is 8/20µs, the impulse current with a peak value of 10 kA and an impulse voltage with a waveform of 1.2/50 µs and a peak value of 20 kV should be in line with the insulation level of the step-up transformer Match. The arrester should have a test report or certificate that meets the above requirements. The grounding wire of the arrester should be specially designed with a cross-section not less than 10 mm2 copper wire.

4.5.5 Protection against electric shock

The dimmer should take protective measures to prevent accidental contact with live parts with a voltage exceeding 50 V. Doors or doors that may touch dangerous voltages after opening the cover should also be marked with a warning of "Dangerous voltage inside, pay attention to safety" or similar warning signs against electric shock.

For electrical components installed in equipment, one or more of the following measures can be taken.

a) Use insulating materials to completely wrap the live parts or use baffles to cover the live parts to ensure that the door is not accidentally touched when the door is opened Live parts

b) The equipment adopts an interlocking mechanism, which can only be opened after the power switch is turned off. When the device door is open, the power switch cannot be closed.

This kind of interlocking mechanism should allow designated personnel (such as commissioning and maintenance personnel) to access live parts when the equipment is live. When the door closes again when closed, the interlock should automatically recover;

c) Special keys or tools should be used to move, open and disassemble the equipment;

d) When cutting off the circuit, the capacitor should have a discharge circuit. Set warning signs on capacitors that may cause electric shock;

e) Parts such as knobs and buttons should be made of insulating materials that meet the maximum insulation voltage of the equipment or used as a sheath.

The components on the protection circuit are electrically connected safely and reliably.

4.6 Grounding

The metal structure of the dimmer should have a grounding point and a grounding mark. The cross-sectional area of the grounding wire connected to the grounding point should be consistent with Meet the requirements of Table 4.

4.7 Step-up transformer

For dimmers equipped with a step-up transformer as its component part, the step-up transformer should be indoor type, cooled by natural air, and can be placed in Inside the cabinet. The rated capacity, temperature rise, rated voltage, ratio and impedance voltage of the step-up transformer should meet the design requirements of the dimmer, and the rest the electrical performance and transformer structure should meet the requirements of GB 1094.11.The temperature rise value of the step-up transformer of the B and C dimmers is in accordance with Appendix A the temperature rise correction coefficient of the step-up transformer is corrected.

In order to meet the matching requirements of the dimmer to the load, the step-up transformer can be provided with a negative tap for reducing the capacity and lead to the terminal.

4.8 Cabinet

4.8.1 Enclosure protection level

The cabinet of the dimmer shall comply with the provisions of 4.12 in GB/T 3797-2005.The protection level of the cabinet shell shall not be lower than IP21.

4.8.2 Shell temperature rise

The temperature rise limit of the accessible shell and cover plate of the dimmer cabinet shall meet the requirements of Table 5.

4.9 Monitoring

The dimmer should be equipped with monitoring and display circuits to display relevant conditions on the panel and send a signal to the interface for remote control points. Dimming the device should have the following monitoring functions.

a) Power on the dimmer;

b) The output volt-ampere number is lower than normal by more than 10% (not included);

c) The actual output current does not match the selected level;

d) The insulation resistance of the load circuit drops below one or two preset limits and lasts for more than 5s (optional item);

e) The number of damaged lights exceeds the preset limit (optional item);

f) The dimmer is in the local/remote control state;

g) The dimmer shuts down due to open circuit protection;

h) The dimmer shuts down due to overcurrent protection.

4.10 Instrument and display

The following operating information is displayed on the panel of the dimmer using instruments, lights or characters.

a) The effective value of the output current;

b) The effective value of the output voltage;

c) The dimmer is in the local/remote control state;

d) The fault category that caused the protection circuit to operate;

e) Cumulative operating hours and equivalent 5-level output current cumulative operating hours (can be manually set to zero, optional items);

f) Display of monitoring items specified in 4.9 (optional items).

4.11 Vibration resistance

The dimmer should be able to withstand drops and shocks during transportation and installation.

4.12 Optional accessories

4.12.1 General requirements

The dimmer manufacturer shall have the ability to provide optional accessories required by 4.12.2 to 4.12.3.

4.12.2 Ground fault detection device

A ground fault detection device can be installed in the dimmer to monitor the insulation resistance of the light circuit to the ground. Load on the light circuit to the ground the maximum detection voltage is limited to 500 V DC. The detection range of the insulation resistance of the ground fault detection device should be at least 10 kohm~50 Mohm.

The device should provide at least two levels of warning and alarm. The limit values of the two levels should be set on the device or dimmer. Dimmer Warning and alarm information should be provided in both the local and remote control state.

4.12.3 Bad light detection device

A broken light detection device (or with this function) can be installed in the dimmer to detect the number of broken lights in the light circuit.

The bad light detection should be able to be carried out at least at the two highest current levels of the dimmer and 25%~100% rated load. The detection accuracy should be Meet the following requirements.

--When the percentage of the number of broken lights in the total number of lights is not more than 10%, the accuracy is not less than 1%;

--When the percentage of the number of broken lights in the total number of lights is 10% to 30%, the accuracy is not less than 2%.

The accuracy of bad light detection applies to the following conditions.

--All isolation transformers in the series circuit are of the same type;

--All lamps in the series circuit have the same power;

--Bad lamp failure should cause the corresponding isolation transformer secondary to open circuit.

The device should provide at least two levels of warning and alarm. The limit values of the two levels should be set on the device or dimmer. When chaining back when the number of broken lights in the road exceeds the preset limit value, the dimmer should generate a warning or alarm. The dimmer should work both locally and remotely Provide warning and alarm information.