Carbest MC4 solar connector assembly wrenches - set of 2, orange polyamide, for tightening and unlocking plugs
- Set of two Carbest assembly wrenches made of orange polyamide. They are used for assembling and disassembling plugs and sockets compatible with the MC4 standard in solar installations.
MC4 connectors are found wherever a solar panel on a camper connects to the cable leading to the charge controller. Their advantage is a sealed design and a latch that keeps the plug from coming apart on bumpy roads. The same advantage becomes a problem during installation: the cable gland nut is hard to tighten by hand enough for the seal to grip the cable, and the latch cannot be released without the right tool. Pliers with metal jaws scratch and squeeze the housing, and a cracked housing is no longer watertight. The Carbest set consists of two polyamide assembly wrenches designed for assembling and disassembling plugs and sockets compatible with the MC4 standard. You hold the connector body with one wrench, turn the nut with the other, and use the tips to release the latch when disconnecting. The wrenches are bright orange, so they are easy to find in a toolbox or an underfloor locker.
Key features
- set of two assembly wrenches
- for plugs and sockets compatible with the MC4 standard
- assembly and disassembly of connectors in a solar installation
- material: polyamide, which does not scratch the connector housing like metal does
- orange colour, easy to spot in a toolbox
- flat shape, fits in any drawer
What the wrenches are for
An MC4 connector consists of a body and a cable gland nut that presses the seal onto the cable insulation. When plug and socket are joined, latches lock the connection. The assembly wrenches help with three jobs: tightening the gland nut after crimping the contact onto the cable, loosening the nut when the connector has to be moved to another cable, and releasing the latch when separating plug and socket. You do this without pulling on the cables and without metal tools that could damage the housing.
How they are built
- Each wrench is a flat, rigid polyamide bar.
- At one end there is an open jaw with teeth on the inside, which you place around the nut or connector body from the side without disconnecting the cable.
- In the middle there are round openings with lugs that fit over the body of the plug and socket.
- At the ends there are two narrow tips for pressing the latches when disconnecting.
- The two wrenches have different shapes, so one fits the plug side and the other the socket side.
Tightening the cable gland nut
- First crimp the contact onto the cable with a crimping tool and push it into the body until it clicks.
- Screw the gland nut on by hand.
- Hold the connector body with one wrench so it does not turn.
- Tighten the nut with the other wrench until the seal grips the cable insulation firmly.
- Do not overtighten, because an overtightened nut can damage the seal.
Separating plug and socket
- Before disconnecting, switch off the loads and disconnect the panel from the charge controller or cover it, because a panel in sunlight produces voltage.
- Never disconnect an MC4 connector under load, that is while current is flowing through it.
- Insert the tips of the wrench into the latch positions on the sides of the connection.
- Press the latches and pull plug and socket apart by the housings, not by the cables.
- After disconnecting, protect the connector ends from water and dirt.
Where they come in handy
The wrenches are useful when first fitting a panel to the roof of a camper or caravan, when replacing a panel or a charge controller, when extending cables and when tracing a fault, where the installation has to be disconnected and checked section by section. They are also handy with folding panels and solar cases with MC4 connectors that you connect and disconnect at every stop. It is worth keeping them in the vehicle together with a spare pair of connectors.
Why not pliers
- Metal jaws scratch and squeeze the plastic housing, which can make it crack.
- A cracked or deformed housing is no longer watertight and moisture gets to the contacts.
- Moisture in the connector leads to corrosion of the contacts and higher contact resistance.
- A wrench grips the nut around its whole circumference, so the force is spread evenly.
What to keep in mind
- The wrenches are designed for connectors compatible with the MC4 standard. If you have other solar connectors, compare their shape with the photo.
- The wrenches do not crimp contacts onto the cable. You need a separate crimping tool for MC4 contacts for that.
- Work in dry weather and on dry connectors.
- After assembly, check that plug and socket are latched and cannot be pulled apart by hand.
Good to know
- The set contains two assembly wrenches.
- The wrenches are light and flat and take up no space in a locker.
- You will find matching MC4 connectors below.
Matching connectors
- Carbest MC4 solar connector - set of 2 - plug and socket for single-core solar cables, which you can tighten, loosen and unlock with these wrenches
Technical data
| Parameter | Value |
|---|---|
| Type | assembly wrenches for solar connectors |
| Brand | Carbest |
| Fits | plugs and sockets compatible with the MC4 standard |
| Use | assembling and disassembling connectors, tightening the gland nut, releasing the latch |
| Material | polyamide |
| Colour | orange |
| Set includes | 2 assembly wrenches |
Frequently asked questions
Do these wrenches fit my solar connectors?
They are designed for plugs and sockets compatible with the MC4 standard. If you are not sure which type of connector you have, compare its shape with the photo of the wrenches.
Why two wrenches?
You hold the connector body with one and turn the gland nut with the other. The same applies when disconnecting: each wrench fits a different side of the connection.
Can I crimp the contacts onto the cable with these wrenches?
No. Contacts are crimped onto the cable with a crimping tool. The wrenches are for tightening and separating a finished connector.
Can I disconnect the connector while the panel is in the sun?
First switch off the loads and disconnect the panel from the controller or cover it. MC4 connectors must not be disconnected while current is flowing through them.
Manufacturer
Carbest, Boschring 10, 63329 Egelsbach, Germany.