Model Interpretation

9907: ProTech203 overspeed protection full series code;

149: 120Vac/DC universal power supply version, triple independent MPU speed input, front-panel local programming & display configuration standard specification.

Technical Specifications

Electrical Parameters

Power Input: 120Vac / 120Vdc universal dual input, three channels isolated power supply respectively

Operating Temp: -25℃ ~ +60℃ (-13℉~+140℉); Storage: -40℃~+85℃, RH 5%~95% non-condensing

Overall Dimension: 482.6(W)×311(H)×142.7(D)mm(19×12.244×5.62inch), Net Weight＜7.72kg(17lbs)

Protection Class: Front panel NEMA4/4X, IP54 dust & splash resistant

Speed Channel Parameter

Speed Setting Range: 250rpm~25000rpm adjustable overspeed trip threshold

MPU Matching: Pickup gear tooth 20~120 configurable; MPU fault timeout 1s~533min20s programmable; MPU failure alarming threshold 100~25000rpm

Discrete Output: Independent relay trip contact per channel + common voting trip dry contact for emergency shutoff valve interlock

Interface and Communication Configuration

Front Panel: Three separated 2×16 character LCD + membrane keypad for respective channel parameter setup, fault code reading and on-site overspeed simulation test

Rear Terminal Block: Hard-wired terminals for 3-channel magnetic pickup signal input, power supply wiring, trip relay output, alarm signal wiring

Communication: Optional serial communication for DCS remote parameter readback and fault uploading

Core Functions

Triple redundant independent speed acquisition, hardware 2-out-of-3 voting logic to prevent single sensor/module fault causing false trip or protection failure

Programmable overspeed trip value, pickup loss detection, speed abnormal alarming and relay output interlock for turbine emergency shutdown

Single-channel hot swap maintenance, online single-module calibration and overspeed simulation test without unit outage

Real-time fault self-diagnosis for power anomaly, MPU open/short circuit, internal circuit failure with local display and remote alarm contact output

Applicable Scenarios

Industrial steam turbine, gas turbine generator set, waste heat turbine, blast furnace gas turbine, steam expander overspeed safety protection in captive power plant, petrochemical and metallurgy industries.

Operation and Maintenance Guidelines

Install away from high-power contactor, inverter and strong electromagnetic interference; prevent dust, oil mist and moisture penetrating cabinet interior

Periodically tighten rear wiring terminals to avoid loose pickup wiring leading to speed signal deviation and false protection action

Replacement spare part must adopt original 9907-149; reset overspeed setpoint and MPU tooth parameter after replacement before unit commissioning

For protection action fault, check front panel channel fault code firstly to locate pickup fault, power failure or internal module damage source