Samlex America MC4-2 - Manual

3 2
Wire Connections on Solar Panels (See Fig. 3)
Most solar panels come with approximately 3 ft of Positive (‘+’) and Negative (‘-‘) wire. One end of each wire
is connected to the junction box of the panel. In most solar panels (for example, solar panels manufactured
by Samlex Solar), the other end of each wire is terminated with an MC4 connector. The Positive (‘+’) wire has
a Female MC4 Connector and the Negative (‘-‘) wire has a Male MC4 Connector. To extend the length of the
wires of these solar panels for connection to a charge controller, combiner box or grid-connected inverter, an
extension wire is required with corresponding Male and Female MC4 Connectors.
Warning!
When the surface of the solar panel / array is exposed to sunlight, a DC voltage
appears at the output terminals turning it into a live voltage source. For example, a
24 V nominal solar panel may put out an open circuit voltage of around 45 VDC that
may produce electrical shock. Multiple solar panels connected in series (to increase
the output voltage) will putout higher lethal voltages. To avoid any electrical shock
hazard during installation, make sure that the solar panel / array is covered with an
opaque (dark) material to block solar irradiation.
INSTALLATION
Installation procedure (See Fig. 1 and Fig. 2)
The MC4 connectors provided are compatible for use with AWG #10 or AWG #12 wire with outer insulation
diameter 3 – 6 mm. Wires may be single conductor, Type UF (Underground Feeder - marked as sunlight
resistant), Type SE (Service Entrance) or Type USE/USE-2 (Underground Service Entrance).
1. Strip 1/4” of the wire insulation using a wire stripper. Take care not to cut individual strands.
2. Insert the bare conductor into the crimping area (4 of Fig. 1) of the metallic mating contact
and crimp using a special purpose crimping tool. The end may be soldered if the crimping
tool is not available. Take care that the solder does not fl ow beyond the crimp area.
3. Insert the metallic mating contact with the crimped wire through the cable gland and into
the insulated housing, until the metallic pin fi ts snuggly into the housing.
4. Tighten nut (3 of Fig.1) so that the rubber bush is compressed around the wire entry to
ensure proper sealing.
MC4 Connector – Locking Arrangement (Fig. 2)
Two locking tabs (1 of Fig. 2) are provided on the MC4 Female Connector. Two corresponding locking slots (2
of Fig. 2) are provided on the MC4 Male Connector. When the two connectors are coupled, the locking tabs
slide into the locking slots and secure.
To uncouple the two connectors, press the ends of the locking tabs as shown (3 of Fig. 3) to release the
locking mechanism.
1. Locking tabs on the MC4 Female Connector
2. Locking slots on the MC4 Male Connector
3. Press here to release the locking tabs. Make sure that no current is flowing
when uncoupling is attempted.
1 3
3 1 2
2
Fig. 2. Snap-in Locking System
Solar Panel
MC4 Male Connector (Marked “-”)
MC4 Female Connector (Marked “+”)
Fig 3. Solar panel with MC4 Connectors