RS2001 / CEDASPE CPR3, OC, e-DMCR — protective relays for OLTCs and transformers

Description

The group covers Reinhausen protective relays for three cases. The RS2001 is installed on the OLTC of a power transformer, the CEDASPE CPR3 protects a transformer with a conservator, and the CEDASPE OC and e-DMCR are designed for sealed distribution transformers. The set of relays is selected for the transformer type, with a conservator or sealed, and for the signals required by the protection scheme and the monitoring system. All devices output discrete signals to the trip or alarm circuit, and some of them also transmit measured values digitally.

The RS2001 is an oil-flow protective relay. It is installed in the pipe between the OLTC head and the conservator. In the event of an internal fault in the diverter switch oil, a sudden oil surge towards the conservator occurs, and when the flow velocity exceeds the threshold, the relay flap moves from the RESET operating position to the OFF position. Reed contacts send a command to the circuit breaker and the transformer is disconnected. The manual describes both flap positions separately and the procedure for returning the transformer to service, i.e. the relay is reset to RESET manually only after the cause of operation has been established. The housing has degree of protection IP66. For hazardous areas there is the RS 2001-Ex version, whose documentation sets out the measures of the manufacturer and those of the transformer manufacturer or operator, as well as a variant with several reed switches and the test procedure. A separate section covers drying of the transformer in an oven or in the tank, since the relay must withstand this stage without damage.

The CEDASPE CPR3 protects the transformer conservator. When it operates, the signal goes through one or two reed switches, at most one normally open contact or two changeover contacts. The reed switches are connected to the electrical controller and to the transformer monitoring circuit. The device is designed for installation in a pipe of nominal diameter DN25. The manual contains technical data, drawings, personal protective equipment requirements and disposal instructions, and repairs are recommended to be entrusted to the technical service or to personnel trained and authorised by CEDASPE S.r.l.

The CEDASPE OC is designed for hermetically sealed distribution transformers without a conservator. Such a transformer has no gas relay in the classic sense, so protection is based on monitoring what happens inside the sealed tank. The OC documentation covers packing, transport, receipt of goods, maintenance and draining of the insulating liquid. During maintenance, the integrity of the housing and seals and the condition of the cable connections are checked.

The multifunction e-DMCR relay combines four safety and monitoring functions in one device. It measures pressure in the range 0–2000 mbar and temperature 0–125 °C, transmits data via Modbus RTU, housing IP55. The relay fits one-to-one in place of conventional devices, so older sealed transformers can be retrofitted without modifying the cover. The e-DMCR is made by the French company IDEF SYSTEMES. For grid companies, it is a way to obtain digital data from a distribution transformer without a separate monitoring cabinet.

Technical specifications

Customs codes

Codes are for reference: the final code is determined at declaration for the specific model.

Questions and answers