Description
Model 1-OCP (Single Phase)
Application: Open circuit protection for the relay classes through C400 and all metering classes
Frequency: 50-400hZ
Ambient Temperature Range: -30 Deg C to + 55 Deg C
Normal Secondary Current: 5 Amps AC
Short Time Overcurrent: 100 Amps for 1 sec (80 Amps for 2 sec)
Max Continuous Current: 10 Amps through one element or 7.5 Amps through all three independent elements
Terminals: Copper with brass slotted pan head screws, #8-32 X 1⁄4, with cupped washers
Weight: 1.2 lbs
A Current Transformer secondary should never be open circuited while the Current Transformer primary circuit is energized.
The OCP series of Open Circuit Protectors are voltage sensing devices using high-speed shorting SCR switches.
The single element Open Circuit Protector is provided with two terminals for connection across the secondary of the C.T. and in parallel with burden.
The OCP also provides protection against high secondary voltage transients, which may damage the burden or secondary winding.
Metering class C.T.’s with a rating factor of 2 could operate up to 10 amps on a continuous basis. The OCP is designed to tolerate both this condition and (80 amp RMS) for 2 seconds.
Open Circuit Protectors (OCP)
A Current Transformer secondary should never be open circuited while the Current Transformer primary circuit is energized. If this situation should occur there is a possibility of developing extremely high voltages which could be dangerous to personnel or cause an insulation breakdown.
The 1-OCP series of Open Circuit Protectors manufactured by Electromagnetic Industries. Is a voltage sensing devices using high speed shorting SCR switches. When the secondary peak voltage exceeds the clamping voltage value, the SCR operates, shorting the C.T. secondary and reducing the voltage to about 2 volts in less than 1/4 cycle. This process repeats each current polarity reversal. The protection is activated each half cycle.
The single element Open Circuit Protector is provided with two terminals for connection across the secondary of the C.T’s and in parallel with the burden. It can also be connected across the current terminals of a protective relay, meter or other current operated device without affecting the operation of the device. Secondary polarity of the C.T.’s is not critical to the OCP.
The OCP also provides protection against high secondary voltage transients, which may damage the burden or secondary winding.
If the transient voltage exceeds the voltage clamping limit, the Open Circuit Protector will trigger. After triggering, the voltage will fall to about 2 volts and remain there until the next zero crossing of the current waveform at which time the device resets and the cycle repeats as necessary. In the transient mode of protection, triggering will occur only on the half cycle where the transient appears. The leakage current of the OCP is insignificant and will not cause a ratio or phase angle error in the Current Transformer accuracy.
Metering class C.T.’s with a rating factor of 2 could operate up to 10 amps on a continuous basis. The OCP is designed to tolerate both this condition and (80 amps RMS) for 2 seconds.
The 3-OCP series of Open Circuit Protectors manufactured by Electromagnetic Industries. are voltage sensing devices using high speed shorting SCR switches. When the secondary peak voltage exceeds the clamping voltage value, the SCR operates, shorting the C.T. secondary and reducing the voltage to about 2 volts in less than 1/4 cycle. This process repeats each current polarity reversal. The protection is activated each half cycle.
The three element Open Circuit Protector is provided with two terminals (for each phase or circuit) for connection across the secondary of the C.T’s and in parallel with the burden. It can also be connected across the current terminals of a protective relay, meter or other current operated device without affecting the operation of the device. Secondary polarity of the C.T.’s is not critical to the OCP.
The OCP also provides protection against high secondary voltage transients, which may damage the burden or secondary winding. If the transient voltage exceeds the voltage clamping limit, the Open Circuit Protector will trigger. After triggering, the voltage will fall to about 2 volts and remain there until the next zero crossing of the current waveform at which time the device resets and the cycle repeats as necessary. In the transient mode of protection, triggering will occur only on the half cycle where the transient appears. The leakage current of the OCP is insignificant and will not cause a ratio or phase angle error in the Current Transformer accuracy.
Metering class C.T.’s with a rating factor of 2 could operate up to 10 amps on a continuous basis. The OCP is designed to tolerate both this condition and (80 amp RMS) for 2 seconds.
The OCP (Open Circuit Protector) manufactured by Electromagnetic Industries comes in two configurations, single and three phase and three voltage levels, 100, 200 and 400 VAC.
