Version 2.04
| Optidrive ODP-2 Solar Pump User Guide |
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4.2. Protective Earth (PE) Connection
4.2.1. Grounding Guidelines and Lightning Protection
Adequate safety earthing must be provided in accordance with local wiring rules and codes of practice. The ground terminal of
each Optidrive should be connected back to the common safety earth to maintain touch potentials within safe limits. The ground
terminal of each Optidrive should be individually connected DIRECTLY to the site ground bus bar (or Ground Rod). Optidrive ground
connections should not loop from one drive to another, or to, or from any other equipment. Ground impedance must conform to local
safety regulations and/or electrical codes.
To meet UL regulations, UL approved ring crimp terminals should be used for all ground wiring connections.
The integrity of all ground connections should be checked periodically.
4.2.2. Protective Earth Conductor
The Cross sectional area of the PE Conductor must be at least equal to that of the incoming supply conductors.
4.2.3. Motor Ground
The driven motor must be locally connected to a suitable ground location to maintain touch potentials within safe limits. In addition, the
motor ground must be connected to one of the ground terminals on the drive.
4.2.4. Ground Fault Monitoring
As with all inverters, a leakage current to earth can exist. The Optidrive is designed to produce the minimum possible leakage current
whilst complying with worldwide standards. The level of current is affected by motor cable length and type, the effective switching
frequency, the earth connections used and the type of RFI filter installed. If an ELCB (Earth Leakage Circuit Breaker) is to be used, the
following conditions apply:
A Type B Device must be used
The device must be suitable for protecting equipment with a DC component in the leakage current
Individual ELCBs should be used for each Optidrive.
4.2.5. Shield Termination (Cable Screen)
The safety ground terminal provides a grounding point for the motor cable shield. The motor cable shield connected to this terminal
(drive end) should also be connected to the motor frame (motor end). Use a shield terminating or EMI clamp to connect the shield to
the safety ground terminal.
4.2.6. Lightning Protection
Surges induced by lightning are one of the most common causes of failure of the electronics associated with solar pumping systems.
A direct lightning strike would be seen as a very rare event but lightning strikes occurring some distance away from the system can
cause very high electrical fields which can be problematic if not addressed properly.
It is always advisable to ensure that the frames supporting the PV Panels is suitably grounded (earthed) which can provide a low
impedance discharge path to ground (earth) for any induced voltages. In any dry or rocky locations, the grounding rods/cables should
be placed deeper and consideration should be made to this requirement during any excavation phases when preparing the site.
It is also recommended to place a suitable PV surge suppression device for the DC-Side. These are often incorporated in the string
combiner boxes (if used) but should be selected according to the inverter Max Voc Voltage.
4.3. Incoming Power Connection
4.3.1. Suitability
All Optidrive P2 Solar Drive models are designed for use on a dc supply, single phase ac supply or balanced three phase ac supply
depending on the model. For all models and ratings when working with an IT Supply network, or any power supply type where the
phase to earth voltage may exceed the phase to phase voltage (such as ungrounded supplies), the internal EMC filter and surge
protection must be disconnected before connecting the supply.
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Elec
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