What does Vt mean on a capacitor?
Voltage transformers (VT), also called potential transformers (PT), are a parallel-connected type of instrument transformer. They are designed to present a negligible load to the supply being measured and have an accurate voltage ratio and phase relationship to enable accurate secondary connected metering.
What do the letters on a capacitor mean?
Many capacitor manufacturers use a shorthand notation to indicate capacitance on small caps. The resulting number is the capacitance in pF. For example, 101 represents 100 pF: the digits 10 followed by one additional zero. If there are only two digits listed, the number is simply the capacitance in pF.
Why do some capacitors have polarity?
Electrolytic capacitors are polarized components due to their asymmetrical construction and must be operated with a higher voltage (ie, more positive) on the anode than on the cathode at all times. For this reason the anode terminal is marked with a plus sign and the cathode with a minus sign.
What does 25 70 21 Mean on a capacitor?
AMBIENT TEMPERATURE! CMRW, CMRW-S, UCW- -M and CDW lines are identified with 25/85/21, which indicates the minimum operating temperature of-25 ºC, maximum of 85 ºC and 21 severity days to humid heat. The CMLW and CDWV capacitors are identified with 25/70/21; therefore, the maximum temperature must not exceed 70 ºC.
Are capacitors positive or negative?
Electrolytic capacitors have a positive and negative side. To tell which side is which, look for a large stripe or a minus sign (or both) on one side of the capacitor. The lead closest to that stripe or minus sign is the negative lead, and the other lead (which is unlabeled) is the positive lead.
What is the difference between 370 VAC and 440 VAC capacitors?
The simple answer is that the 440 is just build better and can handle higher voltage if necessary. When a 370 is used instead of the correct one it will fail prematurely, because the dielectric that is used to build it can’t handle voltage that high.