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What´s the main difference between one polyester capacitor type X2 and a normal polyester capacitor?
I have one circuit using one C=47nF type X2 (polyester). Instead this capacitor Can I put another one C=100nF (polyester)?
I don't know what is "type X2".
Replacing a good poyester capacitor with another but with more than twice its value might mess-up the circuit, depending on what it does.
I think X represents safetyness of this capacitor. There are X and Y types, one of them could and the other can't harm man when it's damaged. This applies to mains capacitors... I don't know what 2 means though.
What´s the main difference between one polyester capacitor type X2 and a normal polyester capacitor?
I have one circuit using one C=47nF type X2 (polyester). Instead this capacitor Can I put another one C=100nF (polyester)?
Yes, if it is also X2 rated. as pointed out, these have special ratings for safety purposes. If the unit you are changing is UL listed, changing this capacitor will void that certification opening up liability scenarios.
I did a little researche and i find out what zevon8 said...
X class is used across the line voltage, but my line voltage it´s 400V, so i put 2 capacitor of 47nF 275V in series, making 550V and 23nF, but i don´t have my circuit working right.
Conclusion:
- with 230V line voltage and a capacitor type X2 47nF my circuit works great.
- with 400V line voltage and 2 capacitors in series i have problems.
- my circuit has a microcontroller (PIC16F872)
Should i put a larger capacitor or what i sould do?
Read the explaination for series capacitor connection in the following link **broken link removed**
The series circuit offers a higher total voltage rating. The voltage drop across each capacitor adds up to the total applied voltage.
Caution: If the capacitors are different, the voltage will divide itself such that smaller capacitors hog more of the voltage! This is because they all get the same charging current, and voltage is inversely proportional to capacitance.
Worse yet, if one capacitor is slightly leaky, it will gradually transfer its voltage to the others, possibly exceeding their voltage rating in turn. And if one of them punches through its dielectric barrier, it can then damage others in a cascading fashion. This is why series capacitors are generally avoided in power circuits.
In the circuit attatched i used a capacitor X1 400V 47nF, but when my relay goes off my contactor still stays on (i have one output controlling one coil of my contactor). There are any way to discharge my capacitor or to turn off my contactor?
I have one 400V contactor.
If i remove my capacitor i have voltage problems...
In the circuit attatched i used a capacitor X1 400V 47nF, but when my relay goes off my contactor still stays on (i have one output controlling one coil of my contactor). There are any way to discharge my capacitor or to turn off my contactor?
I have one 400V contactor.
If i remove my capacitor i have voltage problems...
If the contactor is staying ON, then the relay contacts must be switched ON as well, quite possibly welded together by the spark when they switched ON?. The charge in the capacitor is discharged by the relay contacts, and could well weld them together?, you should have a resistor in series with the capacitor to reduce the peak current to help prevent this.
Using 10k or 1M resistors is pointless. These are much too high.
I would use 100 Ohm or less. The actual value depends on the inductance of the load. Ideally, it should provide critical or over damping.
Also, the RC does not have to be across the contacts. It could be connected across the switched device (like the diode across the relay coil). Thus the RC is not shorted by the contacts.
Have you measured the resistance of the contacts when the relay is released? This will indicate whether the contacts are welded together.
This is a well known promblem also with the triac RC component. If the load is small (10-30mA), the 47n-100ohm parallel with contact give enough current for load when the contact in OFF position. Without RC the spark make disturbances in TTL,CMOS or proc. cct.
Use 1k resistor and not too high value X2 cap. e.g.10nF
I already tried the solutions of ljcox, but what i understand was that i have to put my RC in paralell between my contactor coil (that' my load)!? I did that and didn´t work. Or you said to put my RC in paralell between my diode taht will turn on my relay?
I also tried Sebi solutions (4 capacitors of 250V and 47nF in series that makes one capacitor of 1000V and 11nF), "one capacitor and R=1K in series", and also didn´t work because i have disturbances in TTL,CMOS or proc. I put a big capacitor 22nF and R=1K and also didn't work.
It's driving me crazy :shock:
I already tried the solutions of ljcox, but what i understand was that i have to put my RC in paralell between my contactor coil (that' my load)!? I did that and didn´t work. Or you said to put my RC in paralell between my diode taht will turn on my relay? :shock:
Hi...
I did that and didn´t work! The contacts are switching a contactor coil that will turn on a motor!
Anyway, for now i will do my command at 230V (using a 230V contactor), till i know how to resolve my problem!
One more thing... In my product if my input is for example L1, and if my phase that goes to my relay contact is for example L2 i have disturbances. I think that's "retorno" (i don't know how to say in english) :lol:
Regards!
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