Home > categories > Electrical Equipment & Supplies > Relays > Relay contact voltage is DC28v and AC240V now I would like to have a problem with DC 220V in contact?
Question:

Relay contact voltage is DC28v and AC240V now I would like to have a problem with DC 220V in contact?

Relay contact voltage is DC28v and AC240V now I would like to have a problem with DC 220V in contact?

Answer:

DC220 words are absolutely unreasonable, unless you use the current is very small! Why the load of a relay is generally a very low voltage DC, AC voltage can be higher! The biggest difference is that due to the different characteristics of DC and AC, DC arc is difficult to pull off! Assuming the nominal is 5A / DC28 / AC240 load, you have to take 220vdc voltage, the current will be very small, even within 1A to use! Otherwise, the relay was burned! Specific to the time of 220VDC, the ability to load the current is how much is not reliable formula calculated! Because the relay design of the gap between the contacts you do not know, did not pass the test argument the load is unreliable!
May 9, 2017
Please note that the DC28v and AC240V are calibrated with different current values. From the insulation strength, the search can withstand AC240V certainly can withstand DC 220V, but the rated current is certainly not the same. As the DC is not zero-crossing time, making the contact breaking broken arc difficult, it should be used in derating. Assuming that AC240V is equivalent to DC 220V, then the rated current of the contact should be reduced to 1/5 or less in the case of direct current. That is to say, assuming that your relay contact nominal AC240V is rated at 5A, then In the case of DC 220V, the current through should not be greater than 1A.
May 9, 2017
There is a problem, as long as it is through DC220V no matter what the load is very easy to relay failure.
May 9, 2017
If the pure resistance load (bulb, electric wire, etc.) can, if the inductive load (motor, solenoid valve, solenoid, etc.), can not be used.
May 9, 2017

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