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6
CONNECTOR SYSTEM FOR CONNECTING SOLAR PANELS
The Positive and Negative outputs of a solar panel are fed through a water tight junction box. Appropriate
size of wires are wired to the junction box for further connections.The solar panels supplied with these kits are
provided with approximately 3 ft. each of Positive & Negative wires that are pre-connected to the junction box.
The free ends of the wires are terminated with special mating type of connectors for ease of extending these
wires for further connections. The special mating type of connectors used for the 3 ft. wires provided with the
solar panels and also for the separate extension wires are as follows:
• "SolarLine - MC4" Series manufactured by Multi Contact
• "Helios - H4" -Series manufactured by Amphenol
Both of above "MC4" & "H4" Series are interchangeable and any one of these may be used in these kits. In this
manual, MC-4 Series will be used for explanations.
6.1. General Information on MC4 Connector System
MC4 Connector System consists of male and female connectors. This type of connector system is easy to
install and uses “snap-in” type of safety locking clips to lock the two mating connectors, thereby, avoiding
unintentional disconnection. Also, the mating contacts are sealed against ingress of dust and water.
Specications are as follows:
• Contact diameter Ø 4 mm
• Maximum rated current - 30 A
• Maximum system voltage - 1000 V
• Degree of ingress protection when connected and properly locked - IP67
• Temperature range 40°C to +90°C
• TÜV Rheinland – type approved
6.2. MC4 Connectors (Fig. 6.2)
The MC4 Connectors mentioned in this manual have been designated “Male” and “Female” based on the
characteristics of the mating contact inserts inside the terminals.
In the MC4 Male Connector (1 of Fig. 6.2), the internal mating contact insert (2, Fig. 6.2) is a male pin. It has
two slots (3 of Fig. 6.2) for insertion of the two “snap-in” type of locking tabs (6 of Fig. 6.2) of the MC4 Female
Connector (4 of Fig. 6.2) for rm mating connection. This connector is marked "-".
In MC4 Female Connector (4, of Fig. 6.2), the internal mating contact insert (5 of Fig. 6.2) is a female cylindrical
socket. It has two “snap-in” type of locking tabs (6 of Fig. 6.2) that are inserted into the two slots (3 of Fig. 6.2)
in the MC4 Male Connector (1 of Fig. 6.2) for rm mating connection. Wire is crimped to the contact inserts (2
and 5 of Fig. 6.2) using a special purpose crimping tool designed for MC4 connectors. After the wire has been
crimped, the contact insert is required to be seated securely inside the housing and the strain relief / seal (7 of
Fig. 6.2) is to be tightened fully to provide a water-tight seal.
1. MC4 Male connector (marked “-”)
2. Male contact insert
3. Slots for accepting “snap-in” type of locking tabs of the mating MC4 female connector
4. MC4 Female connector (marked “+”)
5. Female contact insert
3. “Snap-in” type of locking tabs of the mating with the slots on the MC4 female connector
7. Strain relief and seal
1
2
6
4
5
3
7
7
6
3
Fig. 6.2. MC4 Male and Female Connectors
Note: Additional pairs of male/female MC4 connectors are also sold separately (Model No. "MC4-2 Kit")
