MC3 connectors are a mostly obsolete type of single contact
connector commonly used for connecting
solar panel
A solar cell panel, solar electric panel, photo-voltaic (PV) module, PV panel or solar panel is an assembly of photovoltaic solar cells mounted in a (usually rectangular) frame, and a neatly organised collection of PV panels is called a pho ...
s. MC3 are named for the original manufacturer Multi-Contact (now part of
Stäubli Electrical Connectors) with a 3 mm² contact assembly pin.
Tritec Energy Multi-Contact Connector Catalogue
/ref> They are typically rated at 20 A and 600 V maximum (UL), although the rating of the connector and cable as a whole may vary.
Physical properties
The MC3 connectors incorporate a flexible watertight
Waterproofing is the process of making an object or structure waterproof or water-resistant so that it remains relatively unaffected by water or resisting the ingress of water under specified conditions. Such items may be used in wet environme ...
seal and are supplied as 'male' and 'female' types to minimise the chance of wrong connections. For proper application usage, they are connected with UV resistant, correct diameter cable. The connector pairs hold together by friction
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding (motion), sliding against each other. There are several types of friction:
*Dry friction is a force that opposes the relative la ...
and suction
Suction is the colloquial term to describe the air pressure differential between areas.
Removing air from a space results in a pressure differential. Suction pressure is therefore limited by external air pressure. Even a perfect vacuum cannot ...
, only.
Obsolescence
MC3 connectors have been largely superseded by MC4 connector
MC4 connectors are single-contact electrical connectors commonly used for connecting solar panels. The MC in MC4 stands for the manufacturer Multi-Contact (now Stäubli Electrical Connectors) and the 4 for the 4 mm diameter contact pin.
...
s due to support being withdrawn by the National Electrical Code
The National Electrical Code (NEC), or NFPA 70, is a regionally adoptable standard for the safe installation of electrical wiring and equipment in the United States. It is part of the National Fire Code series published by the National Fire Pro ...
for solar applications. The MC3 connector does not incorporate a positive locking mechanism and can become disconnected while the solar panels
A solar cell panel, solar electric panel, photo-voltaic (PV) module, PV panel or solar panel is an assembly of photovoltaic solar cells mounted in a (usually rectangular) frame, and a neatly organised collection of PV panels is called a phot ...
are producing electricity causing dangerous arcing
An electric arc, or arc discharge, is an electrical breakdown of a gas that produces a prolonged electrical discharge. The current through a normally nonconductive medium such as air produces a plasma; the plasma may produce visible light. ...
.
References
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Solar panel connectors