How to select an ETApump Submersible Pump Integrated System™

Solar Submersible pumps:

Lift from as deep as 750 feet (230m).
Maximum 16,000 gallons per day (60 cu.m.).

The information on this page refers to the tables shown further in the document.

Definitions

Vertical Lift = total dynamic head, which is also the sum of the vertical distance from the draw-down level in the water source to the pipe outlet or top of storage tank, and vertical distance equivalence resulting from pipe friction losses.

AWG = American Wire Gauge

Climate zone

Three solar radiation zones are shown on the table, defined by PEAK SUN hours/day. 7.5 is average for summer in central and western USA, and for most locations during dry summer weather. In the wintertime, the Portland Oregon region experiences about 4.5 total peak sun hours per day.

Performance related to weather

These systems are selected for optimum daily output in clear, dry weather. For improved performance in cloudy weather, select a system that produces about 50% more water than you require at 4.5 peak sun hours, or ask your supplier for advice. For satisfactory winter performance, it may be necessary to adjust the solar array tilt. This is an easy adjustment to perform, twice per year.

Solar tracking

A solar tracker automatically aims the solar array at the sun throughout the day. In clear weather, tracking increases the daily water volume by about 40% in summer (15% in winter). This is shown on the sizing table, where you can select either fixed or tracked systems. The tracker's drive is non-mechanical (passive) and highly reliable, using only the flow of fluid against gravity. Tracker Option must be specified with the original purchase. For optimum performance during cloudy weather, or with frequent highly turbulent wind, a tracked system is not recommended.

Doubling the daily water volume

Two pump systems can be installed in the same water source if the well casing is not less than 6inches inside diameter. This doubles the daily water volume.

Daily Water Volume for each system is calculated for worst-case installation conditions

Your results may be better.

PV output is degraded 28% for heat (cell temperature at 60°C), dust, and manufacturer's lowest guaranteed output.
Daily volume is calculated by integrating real flow versus realistic solar (PV) output through the day. (peak sun hours/day = kWh/sq.m/day)
Cable losses are included at maximum allowable length.
The solar array is fixed, with tilt angle equal to the latitude of the location. For central USA, seasonal adjustment of the tilt angle increases daily volume by about 8% in the summer, 5% in the winter.
Flow rates may vary +/-10%.

Lift limits

These systems are selected for optimum performance. To allow unexpected drawdown, each system can handle an additional 15% lift.

ETAPUMP Integrated Systems™ Sizing Table

This table version is for 48Volt systems using direct sunlight. An additional table is available that sizes 24Volt and 48Volt systems using batteries. Contact us.

Instructions

Determine the LIFT and DAILY VOLUME required for the application, and the PEAK SUN hours/day for the application location.
Match the LIFT value to the green Vertical Lift values at the top of the table columns. Best to round up. For example, if 130 feet are needed, use 150feet.
Below the green Vertical Lift column you just identified, find the blue DAILY VOLUME values that match or are slightly higher than the ones determined for the application. The column is subdivided into "Fixed" panel and "Tracked" panel system flow rates. "Tracked" panel systems track the sun across the sky, so are able to capture more light-energy and pump more per day.
Note the number of PEAK SUN hours per day in the yellow box to the right. If these are greater than norms in the application area, then look further down in the chosen Vertical Lift column to find DAILY VOLUME that also matches PEAK SUN hours.
Order the system number located below the blue DAILY VOLUME rates identified.
Use the purple PEAK FLOW RATE (GPM) for sizing pipe.
The next row identifies wire size and maximum wire length for use with the pump.

Wire size nearest larger metric equivalents

No.18 AWG is about 1 sq.mm
No.12 AWG is about 4 sq.mm
No.10 AWG is about 6 sq.mm
No.8 AWG is about 10 sq.mm
No.6 AWG is about 16 sq.mm

Wire sizes, Example

Pump cable: No.6 = AWG / 565 ft. = maximum allowable length of controller to pump for that (No.6) wire size. For each 150% increase in length, the next larger wire size is required. For each 33% decrease in length, the next smaller wire size is allowed.

Array to Controller: If less than 20 feet (3m), use at least No.10 wire size.

Controller to Low-water Probe: Use No.18 minimum, 2-conductor wire.

Controller to Float Switch: Use No.18 minimum, 2-conductor wire.

For ETA systems with last 3 digits between 240 and 600, use 4inch Schedule 40 pipe
For ETA systems with last 3 digits between 720 and 900, use 6inch Schedule 40 pipe

ETA-75C, ETA-14 and ETA-20 use Pump Outlet pipe size of 1 1/4inch NPT. All other ETA pumps use 1inch NPT pipe size at the pump outlet.

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