Shunt releases are devices that are installed with circuit breakers. Most often, models are used in the design of ventilation. It is also important to note that the releases are capable of being operated with load switches.
Manufacturers make models for 20, 24 and 30 A. The design of the device may vary. In order to understand this issue in more detail, you should consider the standard release circuit.
Scheme of a conventional model
The shunt trip for the circuit breaker has a diode rectifier. Dinistors are used with different conductivity. In this case, expanders are installed with modulators. If we consider modifications for phase switches, then they provide a transceiver. The relay is most often installed at the bottom of the structure.
For safe operation of the release, insulators are used. Contacts are located above the modulator. Transistors are installed opposite each other. Kenotrons are often used with an external winding and are attached to the modulator.
Principle of operation
How does the shunt trip? This question worries many, but the answer to it is extremely simple. In fact, the principle of operation of an independent release is based on changing the position of the contacts. This happens due to the supply of a short pulse from the diode rectifier. In this case, the transistor plays the role of a conductor. Due to the modulator, the frequency of the release can be adjusted. To combat electromagnetic interference, a kenotron is used.
Device connection
How to connect a shunt trip? If we consider ventilation systems, then the device is connected through dinistors. In this case, the output contacts are connected through insulators. Directly, the negative resistance parameter must fluctuate around 25 ohms. Connection to the relay is provided through an expander. When connecting a load switch , check the threshold resistance. The specified parameter must not exceed 30 ohms. The release is locked in the power shield. To check the voltage, you must use the tester.
20 A models
20 A trip units are often used for phase switches. The threshold voltage parameter for the models is around 220 V. Some modifications are made with stabilizers. It is also important to note that trip units with IP20 protection system are on the market. The transistors in them are used broadband type. All this suggests that they can withstand large overloads in the circuit.
Connection to the shield of many models occurs through kenotrons. They are produced most often of a two-contact type. The current conductivity of many models does not exceed 5 microns. It is also important to note that models for ventilation systems are manufactured with condenser modulators. In some cases, they are mounted with expanders. They are excellent for remote control of circuit breakers.
24 A devices
24 A devices consist of diode rectifiers. They are installed with different conductivity. As a rule, the protection system is applied by the IP21 series. However, in this case, much depends on the manufacturer. Modulators are used only orthogonal type. For pulse switches, models based on semiconductor thyristors are suitable.
Stabilizers in devices use low sensitivity. The output voltage of this type of trip unit does not exceed 20 V. On average, the current conductivity is 3 microns. Insulators are used to attach the device to the shield. If we consider modifications without transceivers, then they use a capacitor block. Many modifications are suitable for low voltage circuit breakers.
30 A Modifications
30 A trip units are manufactured with code expanders. The output voltage rating for the models is 35 V. As a rule, rectifiers are used diode type. In this case, the contacts are mounted on moving plates. Transceivers are used with tuning resistors. Many models are connected to the shields via capacitor units. In order to avoid large chain overloads, expansion dinistors are used.
Some releases are based on a bipolar transceiver. Their distinguishing feature is high current conductivity. This parameter fluctuates around 6 microns. However, the disadvantage of such systems is the rapid wear of the capacitors. It is also important to note that the models are not suitable for pulse switches.
Model Z-ASA / 230
Shutdown of ventilation in case of fire through the Z-ASA / 230 shunt trip is very fast. The specified model is made with moving plates. In total there are six pairs of contacts. For pulse switches, this device is ideal. It is also important to note that the model is able to be operated in conditions of high humidity. Directly opening the contacts is very fast. For remote control of the ventilation system, this installation is well suited. The current conductivity of the presented trip unit is 4.5 microns.
In this case, the output voltage on the relay is 30 V. The stabilizer in the device is installed without an adapter. Transistors are used dual type. Cenotron model is not provided. An independent release is connected to the shield via a dinistor. It is installed with one panel, which is located in the lower part of the case. Before connecting the device, the negative resistance in each phase is checked first. It is also important to note that wiring is important to insulate carefully.
Model Z-ASA / 250
Why do I need an independent Z-ASA / 250 release? This model is used exclusively for phase switches. The current conductivity is 4.5 microns. The threshold overload of the device is not more than 24 A. The output voltage to the relay does not exceed 33 V. The rectifier is installed diode type. In total, the device has five pairs of contacts. The modulator of this release is provided with an orthogonal type. To connect the model, a capacitor block is used, which is included in the standard modification kit.
If we talk about design features, it is important to note that the transceiver is used unipolar type. The manufacturer's protection system is provided with the marking IP30. The minimum permissible temperature of the release is not more than -15 gr. The stabilizer is not provided in this configuration.
Model IEK PH47
This shunt release (photo below) is pretty much in demand. First of all, it is important to mention its compactness. A small capacitor block is used to connect to the shield. In total, the model uses two rectifiers. The contacts in this case are provided with a movable type. The expander itself is located at the bottom of the structure along with the relay. The transceiver in this case is missing.
If we talk about the parameters of the release, it is important to note that it maintains the output voltage at 40 V. The threshold overload of the model is 30 A. The minimum allowable temperature of the release does not exceed -10 degrees. The model is not afraid of high humidity. The protection system is standardly used with the marking IP30. Wiring in this case is used with insulators for safe operation.
Model IEK PH48
This shunt release (wiring diagram shown below) is made with two diode-type rectifiers. The relay in the device uses high voltage. The current conductivity parameter is at the level of 4 microns. In total, the device has two resistors. Contacts are mounted on special plates. Directly opening is pretty quick. It is also important to note that the device is allowed to be connected through a capacitor block. The output relay is located at the bottom of the structure.
The modulator is applied orthogonal type. For phase switches, the model is suitable. If we talk about the parameters, it is important to note that the threshold overload is at 24 V. The output voltage on the relay reaches a maximum of 30 V. The minimum permissible temperature of the modification is -15 degrees. The protection system in the trip unit is marked with IP30.
Model IEK PH50
This shunt trip is made for pulse and phase switches. For ventilation systems and drives, it fits well. The current conductivity is about 3 microns. The parameter of negative resistance on the relay reaches a maximum of 46 Ohms. The transceivers in the trip unit are of the bipolar type. In total, the model has three pairs of contacts.
They are mounted on special plates that are located above the relay. The modulator is provided by the manufacturer of the orthogonal type. It is forbidden to connect the model through the capacitor block. Only a kenotron is suitable for this. The minimum permissible release temperature is -10 degrees. The output voltage on the relay reaches a maximum of 40 V.
Model SHUNT 230 VAC
This shunt trip can only be used in conjunction with a phase switch. For remote control of the drive, the model fits perfectly. The expander is used code type. Also of the features it should be noted the presence of tuning resistors. Direct transmission of the signal is due to the diode rectifier. The modulator is used in an orthogonal circuit type. The threshold overload of the system does not exceed 30 A. The minimum permissible release temperature is at -20 degrees.
Model SHUNT 250 VAC
This shunt release (wiring diagram shown below) is made on the basis of a diode rectifier. It is located above the relay. If we talk about the parameters of the device, then the negative resistance of the system is 44 ohms. In this case, the threshold overload is not more than 24 A. There is a compact capacitor block for connecting the modification. Conductors in this case are used with insulators. In total, the model has three pairs of resistors. They are located above the rectifier. In this case, the stabilizer is not provided by the manufacturer. For low-power drives, this model is ideal.
Model S2C-A
This shunt trip can only be used with pulse switches. The rectifier in the device is installed diode type. The relay is used with an expander. The current conductivity is not more than 4.5 microns. Transceivers are mounted above the relay.
The stabilizer in the presented release is not installed. The contacts of the model are located on the plates. The signal is transmitted through an orthogonal modulator. The release is connected via the kenotron. Capacitor units are not suitable for this purpose. The minimum permissible release temperature is at -10 degrees.