Rated operating voltage It refers to the voltage requir […]
Rated operating voltage
It refers to the voltage required by the coil when the relay is working normally, that is, the control voltage of the control circuit. Depending on the type of relay, it can be either an AC voltage or a DC voltage.
2. DC resistance
Refers to the DC resistance of the coil in the relay, which can be measured by a universal meter.
3. Pull-in current
It refers to the minimum current that the three-phase relay can generate the pull-in action. In normal use, the given current must be slightly larger than the pull-in current so that the relay can operate stably. For the working voltage applied to the coil, generally do not exceed 1.5 times the rated working voltage, otherwise a large current will be generated and the coil will be burnt.
4. Release current
It is the maximum current that the relay generates to release. When the current in the state of the relay is reduced to a certain level, the relay will return to the unenergized release state. The current at this time is much smaller than the pull-in current.
5. Contact switching voltage and current
Refers to the voltage and current that the relay is allowed to load. It determines the relay can control the voltage and current, and can not exceed this value when using, otherwise it will easily damage the contacts of the relay.
6. Measuring contact resistance
Use the resistance file of the universal meter to measure the normally closed contact and the dynamic point resistance, the resistance value should be 0, (the contact resistance value can be measured within 100 milliohms in a more precise way); and the normally open contact and movement The resistance of the point is infinite. This makes it possible to distinguish between a normally closed contact and a normally open contact.
7. Measuring coil resistance
The resistance value of the relay coil can be measured by the universal meter R×10 Ω file to judge whether the coil has an open circuit.
8. Measure the pull-in voltage and pull-in current
Find adjustable power supply and ammeter, input a set of voltage to the relay, and connect the current meter in the power supply circuit for monitoring. Slowly increase the power supply voltage and record the pull-in voltage and pull-in current when you hear the relay pick-up sound. For accuracy, you can try to average and try several times.
9. Measure release voltage and release current
It is also connected test as described above. When the relay is pulled in, the power supply voltage is gradually reduced. When the relay is heard again, record the voltage and current at this time. You can also try several times to get the average release. Voltage and release current. Under normal circumstances, the release voltage of the relay is about 10 to 50% of the pull-in voltage. If the release voltage is too small (less than 1/10 of the pull-in voltage), it will not be used normally, which will threaten the stability of the circuit. The work is not reliable.