Archive for category Trip Coil
The Trip Coil Monitor provides four form “C” dry contacts, one for each channel monitored. If the coil system has continuity, the contact is held in the closed position. Each channel is connected in series and forms a closed circuit that, with the use of station DC or AC power, sends an energized signal to the base unit.It ensures that the trip coils are functional and it monitors up to four trip coils simultaneously.The benefits of using trip coil monitor are that it eliminates the need of periodic coil checks and it reduces system down-time by alarming coil failures.
The trip coil monitor is a convenient panel mounted relay that utilizes LEDs for visual indication and an added SCADA alarm feature.The trip coil monitor provides continuous monitoring of the breaker trip coil as well as the breaker’s 52b auxiliary contacts.The trip coil monitor eliminates nuisance alarms via a built in time delay circuit.This provides for a reliable SCADA alarm and local indication when either the trip coil opens or the breaker doesn’t complete its trip operation.The trip coil monitor panel mounted package also has a self-monitoring feature providing both visual and SCADA alarm indication if there is a loss of voltage.
Few Types Of Trip Coil Monitors Are Listed Below :
1. Electroswitch Trip Coil Monitor :
Features Of The Product :
1. LED indication of open trip coils or breaker failure to trip
2. Dual trip coil monitoring option available
3. SCADA indication of open trip coil,loss of voltage or failure of the breaker to trip.
4. Standard alarm time delay
5. Replaceable,Industry standard LED
6. Convenient easy to wire design
7. Standard TCM covers 48-125 VDC applications
Benefits Of The Product :
1. Continuous monitoring of trip coil continuity.
2. Built in delay feature eliminates nuisance alarms.
3. Solid state design prevents false alarms due to magnetic field interference.
4. Minimal behind panel space required.
5. Extended voltage capability to minimize inventory and reduce potential installation errors.
6. Eliminates needs for loss of voltage alarm.
Specification Of The Product :
1. Operating Voltage Range : 37-140 VDC
2. SCADA Output Contact Rating : 100mA MAX
3. Operating Temperature Range : -20C to +55C
4. Standard Alarm Time Delay : 300 millisecond
5. Meets ANSI/IEEE 37.90,UL 105 UL file No E18174,ANSI/IEEE 37.90.1
2. Trip Coil Monitor SEL-2652 :
Apply the SEL-2652 Trip Coil Monitor to verify circuit breaker or lockout relay trip coil and trip circuit connections for continuity. The SEL-2652 is self-powered, displays either circuit breaker or continuity status with an external LED, and reports status to SCADA with a Form C contact.
Specification Of The Product :
1. Eliminate the need to stock different trip coil monitors with the SEL-2652, which has a wide voltage range (48 Vdc to 125 Vdc).
2. Quickly detect circuit breaker status with the SEL-2652A or continuity status with the SEL-2652B using clearly identifiable local indication LEDs available in red and blue.
3. Use convenient remote indication to easily monitor trip circuit health without nuisance alarms during normal circuit breaker operations.
4. Reduce maintenance using this rugged device, designed and tested for substation environments.
5. Install in minutes with panel-mount design and Connectorized terminal block.
A trip unit is electrically connected in parallel with a current limiting polymer element in series with circuit breaker contacts to function as a shunt resistance for the polymer element.It becomes energized by transition of the polymer element to its high resistive state for tripping the breaker contacts. The solenoid may be particularly wound with a resistive wire.
Simplified Circuit Diagram Of Trip Circuit Of A Circuit Breaker :
Here a simplified circuit of a typical relay is given.Basically the relay circuit is a three phase circuit and the contact circuit of relays is very much complicated. This diagram is of single phase simplified circuit to explain the basic action of a relay. Let part A is the circuit to be protected. The current transformer(C.T.) is connected with its primary winding in series with the line to be protected. The secondary winding of the current transformer is connected in series with the relay coil. The relay contacts are the part of a trip circuit of a circuit breaker. The trip circuit consists of a trip coil and a battery, in addition to relay contacts. The trip circuit can operate on a.c. or d.c.
If the fault occurs, Then current through the line connected to A increases to a very high value.Then the current transformer senses this current. Accordingly its secondary current increases which is nothing but the current through a relay coil. Thus the relay contacts get closed mechanically under the influence of such a high fault current. Thus the trip circuit of a circuit breaker gets closed and current starts flowing from battery, through trip coil, in a trip circuit. Thus the trip coil of a circuit breaker gets energized. This activates the circuit breaker opening mechanism, making the circuit breaker open. This isolates the faulty part from rest of the healthy system.