Common faults of Pilz safety relays with contacts and how to deal with them

The most common ones are the following:

(1) Contact failure

1. The phenomenon that cannot be disconnected due to mechanical occlusion of the contact (the needle-like protrusion formed on the contact and the pit biting each other), fusion welding, or cold welding.

2. The phenomenon that the circuit cannot be turned on normally due to the increase and instability of the contact resistance.

3. Due to excessive load, or too small contact capacity, or changes in the nature of the load, etc., the contact cannot be divided and closed due to the failure of the circuit.

4. Due to the voltage is too high, or the contact opening distance becomes smaller, the contact gap re-breakdown failure.

5. Faults that cannot accurately interrupt the circuit due to the high frequency of the power supply or the large capacitance of the contact gap.

6. Contact work errors caused by various environmental conditions that do not meet the requirements.

7. Due to the lack of arc extinguishing devices or measures, or improper parameter selection, the contact is worn, or unnecessary interference is generated.

(2) Coil failure

1. The coil temperature rise exceeds the allowable value due to the change of ambient temperature (exceeding the specified value of technical conditions) and causes damage to the coil insulation; Caused by dampness

severe reduction in margin levels; Internal disconnection or turn-to-turn short circuit due to corrosion.

2. Coil damage due to coil voltage exceeding 1 10% rated voltage.

3. During use and maintenance, the coil insulation may be damaged due to the bump of the tool, or the wire may be broken.

4. Due to the wrong coil voltage, such as connecting the coil with a rated voltage of 110V to the power supply voltage of 220V, or connecting the AC voltage coil to the same level of DC

The voltage rises and the coil burns out immediately.

5. The AC coil may not be engaged due to the coil voltage exceeding 1 10% of the rated voltage, or the operating frequency is too high, or when the voltage is lower than 85% of the rated voltage

and burned out.

6. When the AC coil is connected to the voltage, the armature may not be closed and the coil burns out due to the transmission mechanism is ineffective or stuck.

(3) Magnetic circuit failure

1. The wear of the edges and corners and the rotating shaft leads to the failure of the armature to rotate or get stuck.

2. IN SOME DC PILZ SAFETY RELAYS, DUE TO MECHANICAL WEAR, OR DAMAGE TO THE NON-MAGNETIC GASKET, THE MINIMUM AIR GAP AFTER THE ARMATURE IS CLOSED BECOMES SMALLER, AND THE REMANENCE IS OVER

large, resulting in a failure that the armature cannot be released.

3. When the magnetic ring on the core of the AC Pilz safety relay is broken, or when the armature and the pole surface of the core are rusted or impurities invade, the armature will vibrate and produce noise.

4. In the E-type iron core of the AC PIL Z safety relay, when the air gap of the center column disappears due to the wear of the cores on both sides, the armature will be stuck to the fault.

(4) Other troubleshooting

Such as various parts deformed or loose, mechanical damage, cracking or peeling of the plating, the insulation between the live part and the shell is not enough, and the back excitation spring is due to fatigue

Loss of elasticity, improper adjustment of various setting values, the product has reached the rated life, etc.

THERE ARE MANY REASONS WHY PILZ SAFETY RELAYS FAIL, AND IN ADDITION TO THE QUALITY OF THE PRODUCTS REQUIRED BY THE MANUFACTURER, CORRECT USE AND CAREFUL MAINTENANCE ARE ALSO MINIMIZED

barriers, an important part of ensuring reliable work.

Common faults of Pilz safety relays with contacts and how to deal with them

Common faults of Pilz safety relays with contacts and how to deal with them

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