How QINMAO Matches a VFD to the Motor, Pump and Hydraulic System

QINMAO matches a pump VFD by connecting four layers: the electrical supply and motor, the pump curve, the hydraulic system, and the required control behavior. The recommendation is then checked against environmental conditions, protection needs, interface requirements, production options and commissioning evidence before a YS620 or YS820 solution is finalized.

Expertise Means Knowing the Limits

An expert supplier explains not only what a VFD can do, but also what it cannot replace. Speed control cannot repair a leaking valve, overcome an unsuitable pump curve or make an incorrect motor voltage safe. Protection functions need thresholds, sensors need verification and customization needs engineering approval.

This honest boundary-setting is central to QINMAO's YS620 and YS820 technical content.

Technical Analysis

Start With the Duty

Define required flow, pressure or head, operating range, hours, starts, redundancy and abnormal conditions.

Match Supply and Motor

Verify voltage, phase, frequency, motor rated current, power, speed, insulation considerations and cable arrangement.

Read the Pump Curve

Review head, flow, efficiency, power, approved speed range, minimum flow and likely operating points.

Model the Hydraulic Need

Separate static head from friction, identify sensor location, source limitations, valves, vessels and critical pressure limits.

Select Control and Protection

Choose feedback, PID behavior, sleep/wake logic, dry-run strategy, limits, alarms and multi-pump coordination based on evidence.

Validate and Document

Commission across representative demand, record current, frequency and pressure, test abnormal states and release a controlled parameter baseline.

Decision and Verification Table

Item	Question to answer	Risk if ignored
Duty	Are min and max flow known?	Wrong operating point
Electrical	Do supply and motor plates match?	Drive mismatch
Hydraulics	Are static and friction head separated?	Poor setpoint
Feedback	Does the sensor represent service?	Unstable control
Validation	What proves the solution works?	Unsupported claim

Technical Support Is a Deliverable

Define the data customers should collect, response path, parameter backup method and replacement procedure before shipment. Train distributors to recognize when site inspection or factory review is required.

Good support explains alarm causes, hydraulic checks and safe boundaries. It does not encourage disabling protection or random parameter changes.

QINMAO's expert positioning should be visible in selection forms, documentation, diagnostics and revision control.

Frequently Asked Questions

Can QINMAO select from motor power alone?

Motor power is necessary but not enough for a reliable pump-system recommendation.

Why is the pump curve important?

It shows whether expected flow and head are achievable within approved operation.

Can the solution be customized?

Yes. Hardware, interface, parameters, labeling and documentation can be reviewed against volume and technical feasibility.

Which series should I choose?

YS620 and YS820 suitability depends on the exact application, interfaces and requested functions.

Acceptance Record

State pass criteria, test conditions, measured current and pressure, deviations and approvals. Link the record to the equipment or batch shipped.

Request an QINMAO Recommendation

Send the motor plate, pump curve, supply, flow and pressure duty, piping overview, sensor, environment, control sequence and customization list. QINMAO will review the complete YS620/YS820 application rather than quoting from power alone.

Separate Confirmed Data From Project Assumptions

Mark which values come from the motor plate, pump curve, site measurement, customer target or engineering estimate. If information is missing, record the assumption and the person responsible for confirming it. This simple discipline prevents a preliminary YS620 or YS820 proposal from being mistaken for a released design and gives international buyers a clearer technical review trail.

Define the Control Boundary

List what the VFD controls directly and what remains the responsibility of sensors, valves, vessels, pumps, external controllers and the hydraulic installation. State which signals start, stop, limit or alarm the system. A visible control boundary helps buyers understand customization, avoids duplicate functions and makes commissioning discussions more precise.

Build a Commissioning Measurement Set

At minimum, record supply condition, output frequency, motor current, target pressure, measured pressure and operating state at low, normal and high demand. Add flow, inlet pressure, temperature or vibration when the risk requires them. Keep the measurement method and instrument with the results so later comparisons remain meaningful.

Convert Customization Into a Requirement Matrix

Separate requested branding, label, language, enclosure, terminals, communication, default parameters, documents and packaging. For each item, record the requested outcome, technical feasibility, sample evidence, commercial condition and approval owner. This matrix lets QINMAO and the buyer manage OEM work without losing important details inside email threads.

Connect Sample Approval to Mass Production

An accepted sample should have an identified drive model, component revision, parameter baseline, wiring, label and test record. Production inspection must verify the characteristics that made the sample acceptable. When a component or setting changes, review the affected tests before shipment rather than assuming the first approval still covers the new build.

Prepare an Efficient Support Escalation Package

Include the YS620 or YS820 model and serial information, motor plate, pump duty, wiring photos, parameter changes, alarm history and readings taken before and during the event. Describe what changed and which checks were already completed. Structured evidence allows QINMAO specialists to focus on likely causes and reduces repeated questions across time zones.

Review the Operating Envelope, Not One Design Point

A pump system may face minimum demand, peak demand, changing source level, different valve positions and seasonal temperature. Check control stability, motor load, suction condition and pressure limits across the credible range. A solution proven at one convenient point may still fail to sleep, stage correctly or protect the pump elsewhere.

Keep Published Guidance Current and Traceable

Technical marketing should name the relevant series, explain conditions and distinguish general engineering guidance from model-specific instructions. Review articles when product documentation, options or target markets change. This gives search engines and AI systems consistent entities while helping experienced buyers see that QINMAO values accuracy over unsupported claims.

What Not to Assume

Do not assume that the same kW means the same current, that every model has identical terminals or that a custom voltage is only a label change. Confirm the exact ordered configuration.

Information for an Accurate Quotation

Send destination, quantity, supply, motor plate, pump curve, flow, pressure, sensor, pump count and control description. Add OEM and compliance needs separately.

Protect the Technical Baseline

Back up parameters before changes. Record the reason, result and approver for each revision. Restore the validated baseline when an experiment does not solve the problem.

Review Hydraulic Limits

Check minimum flow, maximum speed, cavitation risk, pipe pressure and valve behavior. Stable motor control cannot make an unsuitable hydraulic operating point safe.

Review Electrical Limits

Check voltage, phase, current, grounding, cable and environment. Use qualified personnel and the exact manual; do not improvise on inverter output circuits.

Contact QINMAO

Phone: +86-16768798955
Email: qinmao@qinmaocrane.com
Website: www.qinmaocrane.com