Lorentz Dankoff/Lorentz Disconnect & Jct Box

The junction box is normally mounted on the PV array pole near the pump controller.  It contains a large terminal block where critical electrical connections are made.  The PV array is connected to the system through a disconnect switch in the junction box.  There are sets of terminals for a low water sensor probe, an on/off float switch from a water storage tank, pump connections, and grounding connections.

The pre-wired junction box terminals will handle pump wires as large as #6 (13 sq. mm). If large wires cannot be accommodated easily in the box, you can join them to smaller wires in the junction box. #12 (4 sq. mm) or larger is acceptable for this very short length. Do NOT remove terminal screws. If the key to the junction box gets lost, it can be opened with a screwdriver.

Use conduit or strong, high-quality outdoor cable for connections. Where cables enter the junction box, install sealed strain-relief cable clamps. Keep the controller and junction box sealed Unused holes must be sealed to keep out animals, insects, water and dirt. Each hole is supplied with a rubber plug that can be kept in place for this purpose.

Ground connections at the controller The controller and junction box have redundant ground terminals inside. They are all connected in common with the metal enclosures of both the controller and the junction box. Ground connections can be made to any of these points.

Disconnect Switch
The disconnect switch satisfies National Electrical Code requirements for a safety disconnect between the solar array and the controller. During installation and maintenance, switch off the disconnect switch to prevent shock and arc burn hazard.

Ground connections
The two ground terminals in the junction box are bonded together and are also bonded to the metallic enclosures of both the junction box and the controller. See Section 5.2

Power In
Ensure that the solar array DISCONNECT SWITCH (or battery fuse or circuit breaker)- is OFF. Connect the power from the solar array to the input terminals in the junction box. Observe polarity. If your wires are not clearly marked +/–, test them using a DC voltmeter or multitester.

Pump
Three color coded wires must be connected so that the pump rotates in the proper direction or the pump won't work and could be damaged if runn too long in reverse.

Low Water Probe
The low water probe, if used, must be connected to the junction box.  This will shut off the pump if the water level in the well is too low.  If the well produces a reliable volume of water the probe can be eliminated and replaced by a short jumper connecting the probe's two terminals in the junction box.

Float Switch
Automatic Control for Full-Tank Shutoff. A connection is made at the factory between terminals 4 and 5. If you are NOT using a float switch, leave this connection in place.