RELAYS
Reverse Power Relay - ACCUM31/33

An essential Relay when Generators are used in synchronization with other Generators.

When two alternators are running in parallel and if engine of any of the alternators develops trouble then the other good alternator will force drive the damaged engine by making the alternator of the damaged engine run as a motor and thereby result in a severe damage to the second engine.

These Relays provide a sensitive, accurate and economical protection against motoring conditions in diesel alternators and back pressure turbines.

Special Features
This is an induction disc type relay with inverse time characteristics. The inverse time characteristics are specially suited for Diesel Generator set since they provide :-

• Extremely fast tripping during severe faults.
• Prevents inadvertent tripping due to short duration of minor motoring action caused by sudden loss of load or due to maladjustment of throttle settings of two engines.
• It is extremely simple in construction thereby making maintenance most easy.
• It is immune to voltage surges normally occurring in D.G. Sets.
• It is type tested to IS-3231
• It is suitable to operate up to 50° C Ambient temperature which some times do occur in engine rooms.
• Relays are provided with standard 230V AC auxiliary voltage rating and there is no need to provide auxiliary D.C.supply unless required.

Maximum Torque Angle
Develops maximum torque when the applied voltage lags the applied current by 30° . It can operate even at Extremely Low Power Factors Occurring during severe faults.

Settings & Operating Time
Normally 0-20% continuously adjustable is provided. Timings obtained are in inverse time characteristics.

Burdens
Current coil 1VA, Voltage coil 10VA

Configuration
ACCUM31 (single element), ACCUM33 (three element)

Contacts
Up to 4 pairs of self/hand reset contacts with flag in any combination.

Case
ACCUM31 – 170W x 235H x 175D mm (150 x 220mm cutout) ACCUM33 – 475W x 265H x 176D mm (435 x 222mm cutout)