Mercotac® Electrical
Swivel Connectors

Mercotac® Electrical Swivel Connectors operate on a superior principle over traditional slip ring designs. They offer an extremely low resistance electrical connection because the electrical conduction path is a liquid metal which is molecularly bonded to the contacts. The Mercotac® connection is constant and unchanged for the life of the rotary electrical connector. Brush slip rings are usually composed of a rotating metal ring upon which a graphite or metal brush rubs and transfers the electrical signal or current. While brush slip rings are technically simple in operation, this rubbing interface is fraught with problems that include wear, high electrical resistance, oxidation, and resistance fluctuations which causes electrical noise.





Superior Electrical Swivels for Wind Energy

Better than a twisted welding cable or a traditional slip ring

Electrical swivel connectors produced by Mercotac® have been used successfully in the wind energy generation industry on wind turbines and windmills to transfer electricity from the generator in the rotating turret to the electrical cable in the stationary mast or tower.

Some wind energy designs simply use a rubber welding cable to transfer electricity from the generator through the stationary tower. However, a welding cable needs to unwind after twisting a limited number of times from the change in wind direction. Mechanical fatigue will eventually degrade the cable integrity and cause the loss of power from wind generation.

Alternatively, some designs will use a traditional slip ring. Traditional slip rings need continual maintenance to avoid degradation of the rotating electrical connection caused by normal wear and debris from the rubbing contacts.

Mercotac's no-maintenance rotating electrical connectors solve these problems by providing unlimited 360 degree rotation without wear or degradation. Better electrical connections through the Mercotac® slip ring eliminates the need for an active yaw control system to limit the number of turns. They also provide greater efficiency in the transfer of electrical power generation. Mercotac® wind turbine slip rings can also be used for reliably connecting sensors on the turbine blades to position controllers.

Shown below are some of the Mercotac® connectors commonly used in wind turbines. Optional stainless steel ball bearings and protective Boot Kits are available.


P R O D U C T   O V E R V I E W

Model 230
2@30 amps, 250V
Model 235
2@30 amps, 500V
Model 330
3@30 amps, 250V
Model 335
3@30 amps, 500V
Model 435
4@30 amps, 500V
Model 4100 (Discontinued)
3@100, 1@60 amps, 500V
  Model 830
2@4 amps, 6@30 amps, 250V

Mercotac, Inc.
6195 Corte del Cedro #100 Carlsbad, CA 92011 USA
Telephone: (760) 431-7723  Fax: (760) 431-0905
Email: Support:

S P E C I F I C A T I O N S   O V E R V I E W


Conductors Voltage
Max. freq.
Operating temperature
°F (°C) max. / °F (°C) min.
230 2 0-250 30 200 <1m 1800 140 (60) / -20 (-29) 200 >25M
235 2 0-500 30 (@ 500V) 100 <1m 1200 140 (60) / -20 (-29) 400 >50M
330 3 0-250 30 100 <1m 1200 140 (60) / -20 (-29) 300 >25M
335 3 0-500 30 (@ 500V) 100 <1m 500 140 (60) / -20 (-29) 700 >50M
435 4 0-500 30 (@ 500V) 100 <1m 300 140 (60) / -20 (-29) 850 >50M
4100 (Discontinued) 4 0-500 3@100/1@60 100 <1m 100 160 (70) / -20 (-29) 2500 >50M
830 8 0-250 2@4/6@30 100 <1m 200 140 (60) / -20 (-29) 1000 >25M