Bruel-Kjaer -VIBROCONTROL 920
Overview
Bruel-Kjaer VIBROCONTROL 920 is a compact machinery protection and condition monitoring system designed for continuous surveillance of critical rotating equipment such as turbines, compressors, and pumps. It conditions the signal from a single vibration sensor, compares the measured RMS vibration velocity against two independently adjustable limit values, and drives potential-free relay contacts for annunciation and shutdown, giving plant operators real-time visibility into machine health and early warning of developing mechanical problems well before they escalate into unplanned failures.
As the official authorized partner and exclusive regional representative for Bruel & Kjaer Vibro, Seven Star LLC proudly supplies the VIBROCONTROL 920 system and its full range of compatible sensors and accessories to industrial operators across Oman and the GCC. Every system is sourced through Bruel & Kjaer Vibro’s authorized channel, giving plant operators genuine factory support, complete documentation, and confidence that the protection system meets the manufacturer’s specified performance.
Operating Principle
The VIBROCONTROL 920 continuously acquires signals from vibration sensors — either an accelerometer of 10 mV/g or 100 mV/g sensitivity, or an electrodynamic velocity sensor of 70 mV/mm/s or 100 mV/mm/s sensitivity — mounted on the bearing housing of the monitored machine. Onboard signal processing derives the effective (RMS) value of vibration velocity over the 10 to 1000 Hz band and compares it continuously against two configurable limit values, LIM 1 and LIM 2, each with its own adjustable time delay.
When a measured value crosses an alert or danger threshold, the system triggers relay outputs that can annunciate an alarm, initiate a controlled shutdown sequence, or both, depending on how the protection logic is configured for that machine train. This continuous, automated comparison against calibrated thresholds is what allows the VIBROCONTROL 920 to catch developing faults — bearing wear, misalignment, imbalance — long before they would be noticed through periodic manual inspection alone.
Engineering Design of the Bruel-Kjaer VIBROCONTROL 920
The Bruel-Kjaer VIBROCONTROL 920 is built into a compact plastic housing measuring 150 mm × 78 mm × 115 mm (W × H × D) and weighing 920 g, rated IP 20 with a UL94 V-0 fire protection class, which mounts either directly to a panel with two M4 or M5 screws or onto a 35 mm profile rail to EN 50 022 inside a control cabinet. Integration into a plant’s wider distributed control or SCADA system is by hard-wired signals rather than a digital fieldbus: a short-circuit-proof analogue output of 0 to 10 V (load > 10 kΩ) or 0/4 to 20 mA (load < 500 Ω), potential-free relay contacts rated 30 V DC or 300 V AC at 3 A, and a buffered diagnostic output for connecting a portable analyser.
Configuration and commissioning are handled through a front-panel MODE button and three parameter groups that let instrumentation engineers set the measuring range, the two limit values, their time delays, the sensor sensitivity and the relay behaviour without low-level programming, while onboard diagnostics and status indicators simplify day-to-day operation and troubleshooting for control-room and maintenance personnel.
Key Features
The VIBROCONTROL 920 brings proven protection logic and flexible integration to critical machinery monitoring.
- A single measurement channel reports the RMS vibration velocity of one bearing point across a selectable 0–10, 0–20, 0–50 or 0–100 mm/s full-scale range.
- Configurable alarm and trip thresholds allow protection logic to be tailored to each specific machine train and measurement point.
- Hard-wired integration with plant DCS and SCADA systems through a 0/4–20 mA or 0–10 V analogue output and potential-free alarm relays.
- Two independently adjustable limit values, each with a time delay settable from 0 to 100 s, prevent nuisance alarms during start-up and transient events.
- Compliance with international vibration standards such as ISO 10816 ensures alarm logic aligns with recognized industry practice.
- Dedicated configuration software simplifies commissioning and ongoing system management for instrumentation teams.
- Robust industrial-grade construction supports reliable continuous operation in demanding plant environments.
- Fast data acquisition ensures alarm and trip decisions are based on current, representative machine condition data.
Industrial Applications
Across Oman’s power generation, oil and gas, and petrochemical sectors, the VIBROCONTROL 920 protects turbines, compressors, and large pumps where an unplanned failure carries significant safety, environmental, or production risk. Facilities in Muscat’s industrial areas and the Sohar and Salalah economic zones rely on this class of protection system to maintain continuous, automated oversight of critical machine trains that would otherwise depend on periodic manual vibration surveys alone.
As the officially authorized partner for Bruel & Kjaer Vibro, Seven Star LLC distributes the VIBROCONTROL 920 and compatible sensor packages to EPC contractors, plant reliability teams, and rotating-equipment service providers throughout Oman and the GCC, supporting both new-build machinery protection systems and upgrades to aging monitoring infrastructure on operating plant.
Measuring Ranges and Alarm Configuration
The measured variable of the Bruel-Kjaer VIBROCONTROL 920 is the effective (RMS) value of vibration velocity, which is the quantity plant reliability teams normally trend on bearing housings of fans, pumps, motors and gearboxes. Full-scale range is selectable at 0 to 10, 0 to 20, 0 to 50 or 0 to 100 mm/s, with 20 mm/s as the factory default, and measurement accuracy is ±5 % referred to the displayed value. The frequency range is 1 to 1000 Hz or 10 to 1000 Hz depending on the configured lower cut-off, and a VIBROCONTROL 920-2k variant extends the upper limit to 2000 Hz for machines whose fault frequencies sit above the standard band.
Limit-value resolution follows the selected range: 0.1 mm/s on the 0 to 10 and 0 to 20 mm/s ranges, 0.2 mm/s on the 0 to 50 mm/s range and 1 mm/s on the 0 to 100 mm/s range, with factory defaults of 4.5 mm/s for LIM 1 and 7 mm/s for LIM 2. Each limit carries its own delay, adjustable from 0 to 100 s in one-second steps, so a start-up transient does not drive the shutdown relay. Sensor sensitivity is scaled in firmware by a factor of 0.1 to 1.99, allowing the monitor to be matched to the installed transducer without changing hardware. Accelerometers are supplied from the monitor at −24 V DC / 5 mA with a 4 mA constant-current feed into an input impedance below 4 kΩ, and the buffered diagnostic output delivers 1 V peak-to-peak at 1:1 over 10 Hz to 1 kHz into a load above 3.3 kΩ for a portable analyser or data collector, using AC-185 cable up to 20 m.
Power Supply, Environmental Limits and Lifecycle Status
The Bruel-Kjaer VIBROCONTROL 920 accepts either 115 or 230 V AC ±15 % at 50/60 Hz, drawing a maximum of 12 VA, or 24 V DC with a −25 % / +33 % tolerance at a maximum of 7 W; 230 V AC is the standard factory delivery. Only one supply type may be connected at a time, the DC input is protected by a 500 mA slow-blow fine-wire fuse, and the AC input by a temperature fuse in the transformer. Field wiring lands on screw terminals accepting up to 2.5 mm² conductors, and the supply must be routed through a switch or circuit breaker acting as a disconnecting device to IEC 60947-1 and IEC 60947-3.
The working temperature range is 0 to 50 °C with storage from −10 to 70 °C, although one or two units installed inside an AC-2112 housing are derated to a 0 to 40 °C ambient — a detail worth checking against summer cabinet temperatures in Oman. The monitor conforms to EN 61010-1 and EN 61326-1, and Bruel & Kjaer Vibro has evaluated it to DIN EN ISO 13849-1 with an MTTF of 922,441 hours (approximately 105 years) at 50 °C, Performance Level c and Category 1. The VIBROCONTROL 920 is a legacy product, withdrawn by the manufacturer in 2017 and succeeded by the VIBROCONTROL 950 and 960 families, which is precisely why operators of existing installations across the Sultanate of Oman come to Seven Star LLC for verified replacement units and matching sensor sets rather than re-engineering a working protection loop.
Technical Specifications
The table below summarizes the key specifications of the Bruel-Kjaer VIBROCONTROL 920 system.
| Parameter | Specification |
|---|---|
| Model | VIBROCONTROL 920 |
| Type | Compact single-channel vibration monitor, panel or 35 mm rail mounted |
| Input Channels | 1 (accelerometer 10 or 100 mV/g, or velocity sensor 70 or 100 mV/mm/s) |
| Outputs | 0/4–20 mA or 0–10 V analogue; potential-free relays; buffered diagnostic output |
| Standards Compliance | ISO 10816 vibration severity guidance |
| Measured Variable | Vibration velocity, RMS |
| Measuring Ranges | 0–10 / 0–20 / 0–50 / 0–100 mm/s |
| Frequency Range | 1…1000 Hz or 10…1000 Hz (920-2k: to 2000 Hz) |
| Accuracy | ±5 % of displayed value |
| Alarm Limits | LIM 1 and LIM 2, delay 0–100 s each |
| Power Supply | 115/230 V AC ±15 %, max 12 VA; or 24 V DC, max 7 W |
| Enclosure | Plastic, IP 20, UL94 V-0; 150 × 78 × 115 mm; 920 g |
| Temperature | 0 to 50 °C working; −10 to 70 °C storage |
| Typical Application | Turbines, compressors, pumps, critical machine trains |
Request a Quote for Bruel-Kjaer -VIBROCONTROL 920
Seven Star LLC invites plant reliability engineers and procurement teams across Oman and the GCC to submit a formal RFQ for the Bruel-Kjaer VIBROCONTROL 920 protection system and compatible sensors. We maintain regional warehouse stock for rapid delivery, provide full technical datasheets on request, and our instrumentation division is available to help configure a channel and alarm scheme for your specific machine train. As the authorized partner for Bruel & Kjaer Vibro in Oman and the GCC, Seven Star LLC guarantees genuine equipment backed by full manufacturer warranty and local technical support.
Related Products
Related products
Reviews
There are no reviews yet.