- Most PM-KUSUM solar pump failures trace back to wrong sizing or a weak water source, not the pump.
- No water usually means the borewell dropped below the pump — dry-run cut-off is critical.
- Low output is often soiled or shaded panels, a clogged foot valve, or a sizing mismatch.
- Read the USPC error code against the manual before you touch the pump.
- Who pays for a fault depends on the warranty and O&M clause — verify in the tender.
A PM-KUSUM solar pump that fails in the field is your problem for five years. The good news: the same handful of faults come up again and again, and most are preventable. This guide is a working troubleshooting reference for EPCs — the real symptoms, their causes, and the fix that gets the farmer's water back on.
Why do PM-KUSUM solar pumps fail?
PM-KUSUM solar pumps mostly fail because of wrong sizing or a weak water source, not because the pump itself is bad. A pump sized for more water than the borewell can give will run dry, cycle, and burn out. Get the survey and the sizing right and most field failures never happen.
The other failures cluster around a few causes: dirty or shaded panels, loose DC connections, controller faults, and poor earthing. Each shows a clear symptom. Once you can read the symptom, the cause and the fix follow quickly. That is what the next section gives you.
The symptom → cause → fix table
Use this table as your first stop on any service call. Match the symptom the farmer describes, read the likely cause, and apply the fix. Work top to bottom — the common causes are listed first.
Caption: Common field faults for PM-KUSUM solar pumps. Always read the actual error code and the OEM manual. Source: field practice + MNRE technical specification · verify the water-output basis and warranty terms against the current MNRE spec and the tender.
Pump runs but no water comes out
When a pump runs but gives no water, the borewell water level has almost always dropped below the pump and it has lost suction. The motor spins, draws power, and pushes nothing — and if it keeps running dry, it overheats and fails.
The fix, in order
Check the static and dynamic water level first. If the level has fallen, lower the pump (if the borewell allows) or re-survey the source. Confirm the dry-run cut-off is working so the pump stops itself before it cooks. A borewell that cannot sustain the duty needs a smaller pump, not a longer run.
Water output is much lower than expected
Low water output usually comes from wrong sizing, soiled or shaded panels, or a clogged foot valve. The pump works, but it cannot deliver the flow the farmer expected for the head and depth at the site.
Work through the usual suspects
- Sizing — re-check the HP against the total head; a pump under-sized for the depth will always under-deliver.
- Soiling — dusty modules can lose real output; clean them and see if flow recovers.
- Shading — a tree or pole shading part of the array cuts power sharply; clear it.
- Foot valve / strainer — a clogged inlet starves the pump; clean it.
Judge "expected" against the MNRE water-output basis in the technical specification, not the farmer's hope. The water-output basis should match the current MNRE spec, so verify it before you promise a number.
Controller (USPC) errors
A controller error on the universal solar pump controller (USPC) usually points to over or under-voltage, over-temperature, a dry-run cut-off, or a wrong parameter. The controller is protecting the motor — so read the code before you override anything.
Read the code, then act
Every USPC has an error-code list in its manual. Match the code, then fix the cause: ventilate an over-heated controller out of direct sun, correct a wrong parameter, or solve the dry-run condition at the borewell. Do not just reset and restart — a controller that keeps tripping is telling you something real. Our USPC guide covers the controller in depth.
The pump will not start at all
When a pump will not start, the cause is usually no DC power reaching the controller — a blown fuse, a loose DC connection, a dead array on a cloudy start, or a controller fault. Work from the panels to the motor.
A quick start-up check
- Measure the array DC voltage in good sun; a dead array means a wiring or module problem.
- Check the DC fuses and the isolator.
- Re-tighten the DC terminals — a loose connection is a very common no-start.
- Read the controller display for a fault code before suspecting the motor.
Early wear, cycling and burnout
A pump that wears out early is almost always being run dry, over-volted, or poorly earthed. Frequent on-off cycling is the warning sign: the pump is out-running a slow borewell, heating up, and shortening its own life.
Stop the burnout before it starts
Confirm the dry-run protection actually cuts the pump when the water drops. Check earthing and surge protection, because over-voltage and lightning damage motors and controllers. And match the pump duty to the borewell yield — a smaller pump that runs steadily outlasts a big one that cycles all day.
Who pays when a pump fails?
Who pays for a failure depends on the warranty and O&M terms in the tender, which usually put a multi-year maintenance duty on the EPC. A manufacturing fault falls to the OEM warranty; a dry borewell or farmer misuse can sit outside it. (Verify: warranty and O&M clauses that decide fault liability vary by tender — confirm the exact wording in your RFP.)
Why documentation protects your margin
If a fault is a dry borewell, not your workmanship, you need the survey and the service log to prove it. Clean records of the install, the water survey and every service visit are what keep an out-of-scope fault from becoming your cost. The 5-year AMC / O&M guide goes deeper on running the obligation without losing money.
Prevent most failures at install
Most field failures are designed in at the survey and install, so prevention is cheaper than any fix. Get five things right and your service calls drop sharply.
- Honest water survey — size to what the borewell can actually sustain, not the best-case yield.
- Correct sizing — match HP to the real total head and depth; see the sizing guide.
- Working dry-run protection — test it, do not just fit it.
- Proper earthing and surge protection — protects the motor and the USPC.
- Approved, compliant parts — use the right modules and a spec-compliant controller.
How SuryaHub helps you manage faults
A five-year O&M across many pumps is a service operation, and service is where margins quietly leak. SuryaHub logs every call through the mobile field app, tracks the fault, the cause and the warranty in the AMC service module, and schedules visits so nothing slips and every out-of-scope fault is documented. SuryaHub is pre-revenue; the only real pilots are Suryantra Energy and RGESPL, and every figure here is an estimate to verify.
Run a clean 5-year O&M
See how SuryaHub logs faults, warranties and service visits.
Related guides
Frequently asked questions
Why does a PM-KUSUM solar pump run but give no water?+
A PM-KUSUM solar pump usually runs but gives no water because the borewell water level has dropped below the pump and it has lost suction. Check the water level, lower the pump or re-survey the source, and make sure dry-run protection is active so the pump never runs dry and damages itself.
Why is the water output from a solar pump too low?+
Low water output from a solar pump is usually caused by wrong sizing for the head or depth, soiled or shaded panels, or a clogged foot valve or strainer. Re-check the HP against the head, clean the modules and strainer, and confirm the array is unshaded. Match output to the MNRE water-output basis in the spec.
What do solar pump controller errors mean?+
Solar pump controller errors on the universal solar pump controller usually mean over or under-voltage, over-temperature, a dry-run cut-off, or a wrong parameter. Read the exact error code against the USPC manual, reset the parameters, ventilate the controller, and fix the underlying cause before restarting the pump.
How do EPCs stop PM-KUSUM solar pumps from failing?+
EPCs stop PM-KUSUM solar pumps from failing by sizing the pump correctly for the borewell, surveying the water source honestly, fitting working dry-run protection and proper earthing, and using approved modules and a compliant USPC. Most field failures trace back to wrong sizing or a weak water source, not the pump itself.
Who pays when a PM-KUSUM solar pump fails?+
Who pays when a PM-KUSUM solar pump fails depends on the warranty and O&M terms in the tender, which usually put a multi-year maintenance duty on the EPC. Manufacturing faults fall to the OEM warranty, but a dry borewell or farmer misuse can sit outside it. Warranty and O&M terms vary, so verify the exact tender clause.
How does SuryaHub help EPCs manage solar pump faults?+
SuryaHub helps EPCs manage solar pump faults by logging every service call, tracking the fault, the cause and the warranty, and scheduling the five-year O&M across sites so nothing is missed. SuryaHub is pre-revenue; the only real pilots are Suryantra Energy and RGESPL, and all figures here are estimates to verify.
Sources & references
The water-output basis, controller behaviour and warranty pattern come from the MNRE specification and tender practice. Specs and warranty terms move, so confirm against the current MNRE order and your tender.
- Ministry of New & Renewable Energy (MNRE) ↗
PM-KUSUM technical specifications and water-output basis for solar pumps.
- PM-KUSUM National Portal ↗
Component B & C status, brands and scheme rules.
- SECI ↗
Model tender documents and warranty/O&M reference clauses.
Written by the SuryaHub team · reviewed against MNRE technical spec & PM-KUSUM portal sources · updated 19 June 2026.
Method: Faults, causes and fixes are drawn from field practice and the government sources above and re-checked every 30 days. The water-output basis and warranty/O&M terms are estimates to verify with the current MNRE spec / live tender. SuryaHub is pre-revenue; only Suryantra Energy and RGESPL are real pilots.
Change log: 19 Jun 2026 — first published.