SamKing 48V Solar Pump

Based on your specifications for the SamKing 48V Solar Pump (Medium Flow, 60m head, 1½” outlet) with a recommendation for 475W panels (2 pieces) and a Max Input Voltage of 100V, here’s a clear recommendation and key considerations:

Recommended Solar Configuration ✅

1. Panel Setup:
   • Connect the two 475W panels in SERIES.
   • Why Series?
     • Series connection increases voltage while keeping current constant.
     • Total Voltage (Vmp): ~45V per panel × 2 = ~90V (within 100V max).
     • Total Power: 475W × 2 = 950W (exceeds pump needs, ensuring good performance in low light).
2. Critical Checks:
   • Voltage Safety: Panel Voc (Open-Circuit Voltage) must stay ≤100V even in cold weather.
     • Example: If each panel has Voc ≈ 50V, series Voc = 100V (exactly at max limit).
     • Add a safety margin: Ideally, keep total cold Voc < 95V (check panel specs!).
   • Controller Compatibility: Ensure the pump’s built-in MPPT controller accepts ~90V operating voltage.

Key Considerations ⚠️

• Panel Specifications:
  • Verify panel voltages!
    • Ideal Panel Specs: Vmp ≈ 45V, Voc ≤ 48-49V (to stay <100V in series when cold).
  • Avoid panels with high Voc (e.g., >49V each) to prevent overvoltage damage in cold conditions.
• Head & Flow:
  • “60m” likely refers to maximum head (lift). Actual flow rate decreases significantly at high heads.
  • Confirm the pump’s flow rate at your actual head height (e.g., 60m vs. 40m).
• Wiring & Protection:
  • Use 10-12 AWG solar cables (minimizes losses).
  • Install a DC fuse/breaker (≥25A) between panels and pump.
  • Ground panels and pump properly.

What to Do Next:

1. Check Panel Spec Sheets:
   • Confirm Vmp (Operating Voltage) and Voc (Open-Circuit Voltage), especially the temperature coefficient of Voc (critical for cold weather).
2. Pump Manual:
   • Verify MPPT input range (voltage/current limits).
3. Alternative Panels:
   • If your 475W panels have high Voc, consider lower-voltage 450-500W panels (e.g., half-cut cell panels with ~40V Vmp).

Example Setup:

Component	Specification
Pump	SamKing 48V, Max 100V
Solar Panels	2 × 475W
Connection	Series
Total Power	950W
Operating V	~90V (Vmp × 2)
Max Voc	≤100V (must verify!)

Pro Tip: If panel Voc is too high, connect in parallel instead (voltage stays ~45V, current doubles). But this requires thicker cables and performs worse in low light. Series is preferred if voltage stays <100V.

Consult the pump manual or supplier to confirm compatibility before installation! 🌞