Contact Us

Postal Address:
P.O.Box 526
Modderfontein
1645

Tel: +27 11 606 2777
Fax: +27 11 606 8075
E-mail: info@woodbeam.co.za

Auxiliary Flag & Tripping Relays

Along with the industrial plug in relays, WoodBeam is able to offer a wide range of auxiliary relay devices to suit almost every typical substation and industrial application.

Electro-mechanical multi-trip relays remain the preferred option for a wide range of functions such as:

• Interfacing signals from protection relays where the required number of contacts exceed the number of protective relay contacts;
• Circuit breaker tripping where the trip coil power requirements exceed the protective relay contacts capacity;
• Where secure system lockout is required;
• Auxiliary trips to start backup protection timers start disturbance recorders and signal classical SCADA systems;
• Flagged follower relays for transformer oil & winding temperature alarm and trip, buchholz gas & surge;
• Monitor trip supply voltage, the trip circuit & coil integrity through continuous energisation of the relay coil ensuring failure is detected and alarmed;
• Intertripping of switchgear via pilot wires which may have an induced AC voltage. The pilot receive relay can be designed to discriminate between the induced AC voltage yet still provide a high speed trip from the DC trip signal.

Despite the maturity of the technology, electro-mechanical relays provide an array of useful characteristics including:

• High levels of electrical isolation between input and output circuits;
• A huge range of resistance between switch-on/switch-off;
• Many independent isolated outputs may be associated with one input;
• Physical ruggedness. Most relays can withstand massive short term overloads across both actuating and switching components;
• Relays are largely immune to electrical, radio frequency and other forms of radiation;
• High burden versions immune to capacitor discharge currents;
• Actuating voltages and currents are relatively uncritical;
• The operation of the relay is largely self evident making fault finding simpler;
• Innumerable switching configurations are possible;
• High speed operation;
• High visibility mechanical flags and latches provide non volatile memory and reset capabilities without the need for auxiliary supplies;
• Relative compactness considering the number of contacts possible per signal input;
• Proven field reliability;
• May be designed to discriminate between AC & DC inputs.