Servo
Servo Motor
Zhongli Weiye supplies servo motors matched to the valve shaft, linkage geometry and control signal of the modulating burner they drive.
Servo models
Siemens SQM45.295 B9
The Siemens SQM45.295 B9 is a brushless-DC combustion servo motor from the SQM45/48/50 series, driving burner air dampers and gas-…
View details →What the servo motor does on a modulating burner
On a modulating burner the servo motor is the actuator that drives the fuel metering device — a gas butterfly or proportional valve, or the oil regulating valve — in step with the air damper. It is what turns a fixed-output burner into one that follows load, and its linkage and cam settings are established during commissioning so the air-fuel ratio stays correct at every point of the range.
Servo motors are specified by torque, travel angle, drive signal and supply voltage, and by the mechanical coupling to the valve shaft. On many burners a single servo drives both the air damper and the gas valve through a cam and linkage arrangement, so a replacement has to match the original travel and the linkage geometry, not merely the electrical interface.
- Typical symptoms: burner will not modulate, output stuck at high or low fire, servo hums or stalls, output hunting around the setpoint.
- Give us the servo code, or the burner model and a photo of the linkage at its low-fire position.
Buyer Questions
Servo FAQs
Can I replace the servo motor with a different brand?
Only if torque, travel angle, drive signal and — most importantly — the linkage geometry all match what the burner was commissioned with. A servo that turns further or faster than the original will upset the air-fuel ratio at every point of the range. Send the code and a photo of the linkage at low fire and we will confirm the match.