Tank and transformer protection control panel
Rectifier transformer protection tank and control panel
1- The rectifier transformer tank and panel
Rectifier transformers are suitable for installation in any environmental conditions, including: inside the room, in the open space, inside the danger area, etc., according to the IEC60144 standard. In order to protect and paint the body of these devices, according to the customer’s request, liquid alkyd, electrostatic powder, industrial and epoxy, galvanized, etc. coatings are used. In the conditions where the rectifier transformer installation environment is highly corrosive (next to docks or on vessels), the rectifier transformer tank or panel is usually made of stainless steel. Rectifier transformers suitable for installation in open space have a shade to prevent damage to the body of the rectifier transformer from environmental conditions. On the body of the rectifier transformer with oil cooling, an oil dehumidifier is installed to show the oil level, and they also have a calibrated oil temperature display.
2- Control and protection board
In order to protect the constituent components of the rectifier transformer, such as: main transformer, rectifier part, etc., equipment is used to control the incoming electricity, which prevents its application in the event of an error, resulting in damage to the device. Also, the output is equipped with equipment that protects the device against errors such as lightning, reverse current, currents caused by welding, etc. At the same time, measuring instruments are also used to display the required parameters at the input and output. Below we describe the mentioned equipment.
A) Disconnect and connect timer: according to the standards of the cathodic protection system, the criterion for measuring the protection potential is the moment of disconnection of the source of current injection to the structure under protection (Instant Off Potential). As a result, according to the standard, the rectifier transformer should have a disconnect and connect timer for the output of the device, with the ability to set the disconnect and connect time from zero to 300 seconds. On the device, a key is considered to determine the operation of the device in timer or permanent mode.
b) Protection: The following are used to protect different parts of the transformer and rectifiers:
– Automatic switch (MCCB) in alternating current input and DC output (according to the customer’s request)
– Phase control relay (three-phase monitor) to prevent damage to the rectifier transformer in case of an error in the alternating current input
– Super fast fuse suitable for rectifier transformer specifications
– MOV metal oxide varistor arrester
– Filter and inductor to prevent transient states caused by switching
– Output rectifier protection against short circuit using electronic current limiter
– Special fuse to protect the control unit
– DC voltmeter protective fuse
– If requested by the applicant, installation of an overcurrent relay to protect against overload
c) Measuring equipment: normally, a voltmeter is installed at the input (in three-phase devices, a selector switch is also added), voltmeter and ammeter with shunt are installed at the output of the rectifier. According to the customer’s request, installation of other measuring equipment such as ammeter with CT at the entrance, etc. is done.
d) Connections and internal wiring: all the metal parts inside the rectifier transformer panel are connected to the earth terminal of the device. The location of the input and output terminals is chosen in such a way that connections can be made easily. All internal connections are made with a wire with a minimum cross-sectional area of 1.5 mm square along with the relevant tag number.
e) Output filter: If required and requested by the customer, a selfie filter or selfie/capacitor rectifier will be installed at the output.
