GG-21 type reverse power relayDetailed product description：

1 Purpose
The GG-21 reverse power relay is capable of disconnecting the AC generator from the power grid when reverse power occurs.

Overview of Structure 2
Reverse power relay operates based on the principle of induction (with a rotating magnetic field).
The magnetic conductor of the relay consists of two magnetic circuit systems: an upper magnetic circuit system and a lower magnetic circuit system. The current coil is installed in the upper magnetic circuit system and is powered by a current transformer connected to a certain phase of the generator. The voltage coil is composed of two coils connected in series and installed on the lower magnetic circuit system. It can be directly or through a voltage transformer connected to the generator phase voltage.
The relay rotation system has an aluminum disc, which is pressed onto the shaft, and the two ends of the shaft are pressed into steel shaft tips. The rotation system is supported by steel balls through the shaft tips, which are mounted on bearing screws.
A gear is installed on the aluminum disc shaft, which meshes with the gear equipped with a relay moving contact. A balance spring is pressed onto the moving contact gear shaft to establish a reaction torque.
The silver static contacts are fastened between thin bronze sheets and mounted on a plastic seat. The screws used to install the contact seat are used to adjust the position of the relay static contacts. When reverse power occurs, a torque is generated on the disc to close the relay contacts. Under the action of the aluminum disc rotation torque, the relay contacts close, the generator automatic switch trips, the relay coil loses power, and the relay rotation system returns to its original position under the action of the balance spring.
Relays can change power settings by changing the number of turns of the current coil connected to the current transformer. The current coil tap is welded to the socket, which has three sockets. At rated voltage, the corresponding rated power percentages are 6.4, 9.6, and 12.8.

Generator power	Rated current of engine (A) Ie=Pe/SQRT(3) Ve cosΦ c(A)	current transformer transformation ratio	When the rated current of the generator is reached Current Transformer Current I2（A）	Percentage (%) of rated active power of relay at each setting position
				one	two	three
twenty-five forty fifty seventy-five one hundred one hundred and fifty two hundred two hundred and twenty-five two hundred and fifty three hundred four hundred five hundred six hundred six hundred and fifty seven hundred and fifty one thousand	forty-five point two seventy-two point three ninety point four one hundred and thirty-five one hundred and eighty-one two hundred and seventy-one three hundred and sixty-two four hundred and seven four hundred and fifty-one five hundred and forty-two seven hundred and twenty-four nine hundred and three one thousand and eighty one thousand one hundred and seventy one thousand three hundred and fifty one thousand eight hundred and ten	ten fifteen twenty thirty forty sixty eighty one hundred and twenty one hundred and twenty one hundred and twenty one hundred and fifty two hundred three hundred three hundred three hundred four hundred	four point five two four point eight one four point five two four point five two four point five two four point five two four point five two three point three nine three point seven six four point five two four point eight one four point five two three point six two three point nine one four point five two four point five two	seven point zero eight six point six six seven point zero eight seven point zero eight seven point zero eight seven point zero eight seven point zero eight nine point four three eight point five one seven point zero eight six point six six seven point zero eight eight point eight four eight point one eight seven point zero eight seven point zero eight	ten point six two nine point nine eight ten point six two ten point six two ten point six two ten point six two ten point six two fourteen point one five twelve point seven seven ten point six two nine point nine eight ten point six two thirteen point two six twelve point two seven ten point six two ten point six two	fourteen point one six thirteen point two one fourteen point one six fourteen point one six fourteen point one six fourteen point one six fourteen point one six eighteen point eight seven seventeen point zero two fourteen point one six thirteen point three one fourteen point one six seventeen point six eight sixteen point three six fourteen point one six fourteen point one six

The GG-21 reverse power relay can be plugged into the corresponding socket for setting the power of a certain action.
In order to prevent the secondary winding of the current transformer from disconnecting and dangerous high voltage at the terminal, there is a spare plug in the fourth socket.
When converting loads, it is necessary to first insert the spare pin into the socket according to the required operating power. Only after doing so can the first pin be unscrewed and placed into the empty socket.
The relay has a delay that is inversely proportional to the operating power, which is obtained by rotating the aluminum disk of the relay rotation system between the permanent magnet poles of the relay.
By changing the stop block of the relay's moving contact, the set value of the action delay can be altered.
The stop lever is made in the shape of a pointer and can move along the dial. The dial is engraved with readings of 2s, 3s, 7s, 9s, and 12s. The time characteristic curves of 2s, 7s, and 12s are shown in Figure 2
When the contact is closed, the steel stop block located on the moving contact reaches the small magnet installed on the bottom plate of the contact system, thus
Attracted it, ensuring the reliability of circuit contact closure.
The relay magnet, rotating system, and contact system are installed on an aluminum silicon alloy frame, which in turn is mounted on an aluminum silicon alloy base. There are two terminal blocks on the base for connecting wires to relay coils and contacts, and the base is also used to secure relays to the distribution panel.
The relay has a steel casing to protect the mechanism from mechanical damage and prevent water droplets from entering.
The internal wiring of the relay is shown in Figure l

Figure 1



Figure 2

3 Technical data
3.1 Rated voltage: 100V, 127V, 230V, 50HZ.
3.2 Rated current: 5A.
3.3 Maximum sensitivity angle: 30 ° -3 ° (i.e. current leads voltage by 30 °).
3.4 The operating power is 6.4%, 9.6%, and 12.8% of the rated power at rated voltage and maximum sensitivity angle.
The action time at 3.5 1.2 times the action current and maximum sensitivity angle is 2s, 3s, 5s, 7s, 9s, and 12s.
3.6 Return coefficient, that is, the ratio of the return power of the rotating system returning to the initial position to the action power is not less than 0.6 (the action time is set between 2s and 5s).
When using a standard current transformer (COS Φ=0.8), the rated voltage of the generator is VH=400V. The actual operating power of the voltage transformer (400/127V) is shown in Table 1.
3.8 The external dimensions and opening dimensions of the relay are shown in Figure 3 and Figure 4.


Figure 3 Outline dimension diagram of GG-21 reverse power relay

Figure 4 Hole Size Diagram

4 Ordering Instructions
4.1 Product model and name.
4.2 Order quantity and specifications.
4.3 Wiring method. (Before or after the board).