Bernard electric actuators come in a wide range of models, and their greatest strength is tailoring to the user's actual needs — proper selection meets both industrial requirements and maximum economy. By duty they divide into on/off, Modulating II and Modulating III: frequently modulating or critical control valves need Modulating II; valves with modest modulation (360 ops/day, ≤1200 starts/h) and less critical duty can use Modulating III for economy. On/off actuators use 30%-duty motors, adequate for virtually all on/off service.
Bernard actuators offer several ingress-protection levels — IP67 standard, IP68 for the ST series. Explosion-proof versions come in two levels (Eexed and flameproof EExd, standard EExdIIT4); check the explosion-rating mark in the selection table.
The control system is modular for different applications. A unit without controls is a "bare" actuator — gear reduction, torque measurement, limit & torque switches, drive and motor, wired to labeled terminals. The user supplies their own logic control (open/close/stop): more work, but cheaper and fully customizable.
INTEGRAL+ is Bernard's own logic control system and the basic building block: automatic phase correction, phase-loss alarm, motor over-heat and over-torque protection, local switches, remote/local selection; voltage control (10–250 V AC/DC) or dry contacts (internal 24 V DC), plus 4 status relays and 1 fault relay. Plug-in circuit modules and micro-switches let users change defaults on site — closing direction, NO/NC contacts. In conventional control, INTEGRAL+'s reliability and convenience made Bernard actuators world-famous.
POSIGAM+ adds position output and position-control circuits to INTEGRAL+ for Modulating III actuators (2% accuracy) — simple, reliable; high-end users can fit solid-state relays and conductive-plastic potentiometers for better control quality. Its micro-switches set closing direction and signal type (4–20 mA or 0–10 V).
MODUGAM+ likewise adds position output/control circuits to INTEGRAL+, but with premium drive components (solid-state relays, conductive-plastic potentiometers) for 1% accuracy, long life and high reliability — the controller of choice for Modulating II actuators.
Both position systems accept analog (4–20 mA) or pulse (dry-contact) control via a changeover switch — see the relevant literature.
With INTEGRAL+ or above, every Bernard actuator supports fieldbus control: PROFIBUS-DP/DPAI and MODBUS general fieldbuses, plus dedicated DS100/DS200 — the DS200 being redundant fieldbus for the most reliability-critical applications. All are added to INTEGRAL+ as a bus interface board, easy to install and commission. DS100/DS200 need a controller joining actuators to the general bus — lower cost, up to 16 lines × 31 actuators each, 10 km maximum distance. The intelligent control system is Bernard's advanced digital control: a microprocessor core with absolute encoders digitizing position and torque — high precision, genuinely intelligent digital control.
To dispel moisture and prevent condensation, a heater can be fitted inside the actuator housing. Outdoor installations and humid environments should generally have one — yet some users neglect it, and condensation does cause short circuits and mold. We strongly recommend heaters for outdoor actuators or humid indoor climates. Very hot applications (e.g. secondary-air systems in power plants) must not have one.
For long storage in humid environments, keep heater-equipped actuators energized to protect the boards. Otherwise, before energizing, open the main and control compartments: dry any condensation and repair mold first, or the actuator will be damaged.
We often find quarter-turn (90°) actuators that, once connected to the valve, actually travel only 60–80° or less. For on/off duty this hardly matters — operation time is just shorter. For modulating duty it is troublesome: the 4–20 mA signal must correspond to valve position over the actual travel.
Related reading: Bernard brand column | Bernard torque/position setting | Bernard SD series product
