ШУВ vs БУВ: which control unit to choose

An electromagnetic drive must never be wired directly to the mains — a control device always sits between the drive and the supply, regulating coil voltage and protecting the drive by current. We build this device in two designs — the ШУВ cabinet and the БУВ unit (including the БУВ-ш variant) — and which one you need comes down to installation conditions, not preference.

The "ШУВ or БУВ" question almost never comes up in a vacuum: it arises either when ordering a new feeder and specifying the package, or when upgrading a station where the feeder is already in place and the control gear has aged. In both cases the answer follows not from preference but from four facts about the site — where the equipment will physically stand, who sets the output, what drive the feeder has, and how stable the material properties are.

What the control device does in the feeder circuit

An electromagnetic drive runs on regulated, not fixed, voltage: the coil voltage sets the tray amplitude and therefore the output. The control device does three jobs at once — it regulates that voltage, protects the coil by current, and provides start and stop including remotely. It is not an accessory: without it the feeder either does not run at all or runs in a single unregulated mode.

The ranges differ by size. Light-duty feeders with ВЭМ-Л1 and ВЭМ-Л2 drives take 0–250 V at up to 1.5–6 A, ВЭМ-Л3 and ВЭМ-Л4 take 0–300 V at up to 7–10 A, and the heavy ВЭМ-Т series takes 0–300…315 V at up to 12–16 A. Those figures come from the spec table of the specific feeder and decide which control version is suitable at all: a device sized for a light drive will not carry a heavy one.

ШУВ cabinet (IP54)

The ШУВ control cabinet is a stand-alone wall- or floor-mounted enclosure rated IP54, built for shop-floor conditions: dust, occasional splashing, no dedicated switchgear room. Inside is the switching and control gear in a protected housing — the right choice when the control device is physically located next to the feeder rather than in a separate panel room.

The practical meaning of IP54 is simple: the cabinet needs no additional enclosure and survives workshop dust and the odd splash during cleaning. The trade-off is size, and the need for wall or floor space next to the equipment. If there are several feeders in one area, there will be as many cabinets — the standard version serves one feeder.

БУВ unit (IP20)

The БУВ control unit is a compact design rated IP20, meant for mounting inside an existing automation cabinet or in a clean switchgear room where extra enclosure protection is unnecessary. It comes in two service variants: two-side-service БУВ (terminals and components accessible from both sides — convenient for DIN-rail installation in a row with access from either side) and one-side-service БУВ-ш (all connections on one side — for mounting against a wall or at the end of a cabinet run).

The unit wins on packing density: several units fit into one existing automation cabinet, cables from the feeders come to a single point, and servicing happens where the rest of the site automation is serviced. One condition applies — the room must be clean: IP20 protects against contact and large objects, not against dust and moisture.

Comparison

How the version affects feeder behaviour

Enclosure and ingress rating are not the only differences. Within one series there are variants that change how the station behaves:

• With amplitude stabilisation by vibration sensor. A sensor on the tray holds the amplitude steady as bulk density or moisture changes. Without it the feed drifts with the material and the operator has to re-trim the voltage by hand.
• With 4…20 mA (0…10 V) control. The БУВН series accepts a setpoint from the plant control system — the only option if output must change automatically on command rather than by hand.
• For weigh dosing. Versions with the П index switch two output levels remotely: coarse feed up to the setpoint, then fine topping-up.
• For two-stroke drives. Heavy feeders with a two-stroke drive need versions with the 2Т index; a device for a single-stroke drive will not run them.

Decoding of every index and the full list of versions are on the control units page.

Four mistakes that cost money

Putting an IP20 unit in the workshop "just for now". Dust on the board and condensation inside is a matter of months, not years. With no electrical room available, the right answer is a ШУВ cabinet, not a unit in an improvised box.

Choosing a version without a sensor for variable material. If moisture and fraction drift between batches, the feed will drift too — and it will be blamed on the feeder, though the cause is the chosen control version.

Not checking the coil current. Heavy ВЭМ-Т drives draw up to 12–16 A against 1.5–10 A for light ones. The device is matched to the specific drive, and an error here means replacement, not adjustment.

Forgetting service access. A two-side-service БУВ wedged into the end of a cabinet is awkward to work on — for that position there is the БУВ-ш with all connections on one side.

How it looks on typical sites

One feeder under a bin in a crushing plant. No electrical room nearby, dusty environment, control needed locally — a ШУВ cabinet with IP54 goes a few metres from the feeder. The operator sets output from the front panel and no separate room is required.

Four feeders on a raw-material preparation line. The site has an automation cabinet in a clean room with cables already run to it. Four БУВ units on a DIN rail are the better answer: less space, servicing in one place, and adding a fifth feeder needs no new cabinet.

A feeder in a weigh-dosing station. The setpoint comes from a weighing controller and two feed levels are needed — coarse and fine. A version with the П index covers it; the ingress rating follows from where the gear stands.

A line under plant control. Output changes automatically on a 4…20 mA signal — the БУВН series fits, and if the material also varies in moisture, the -Д index keeps the amplitude steady as bulk density changes.

Upgrades: what changes when the feeder stays

A separate case is when the feeder is in place and working and only the control has to change — a site moving to automatic setpoints, a cabinet at the end of its life, or weigh control being added. What matters is that the match is to the electrical parameters, not to the feeder model: drive type (single- or two-stroke), coil voltage range and maximum current. Those three figures are in the spec table of the feeder card, and they decide the control version regardless of the feeder's age.

The reverse — fitting a new feeder to an existing cabinet — works the same way. If the new feeder is in the same drive and current class, the existing control usually stays. Moving from a light drive to a heavy one changes the control along with the feeder: up to 10 A on a ВЭМ-Л4 against up to 16 A on a ВЭМ-Т4 are different devices, not different settings.

What goes wrong with the wrong choice

The symptoms people bring almost always reduce to three. The feeder never reaches rated output — usually short of coil voltage because of an unsuitable version, or limited by current. The feed drifts through the shift — a version without a sensor on material with variable moisture. The feeder runs in bursts under remote control — a mismatch between how the setpoint arrives (relay, 4…20 mA, weighing controller) and what the chosen device can accept.

All three are settled at selection and almost none of them at commissioning. Replacing the control on an installed station means repeating the electrical work and stopping the line.

What to request with the device

Every version has a wiring diagram and a data sheet, and both are worth requesting up front rather than after delivery: the diagram tells the electricians which cables and cross-sections are needed, where the vibration sensor goes on -Д versions, and how the remote control signal is brought in. Documentation for some versions is published on the control units page; the rest we send on request.

Check separately whether the vibration sensor and its cable are included when an amplitude-stabilising version is chosen: these are separate items, and a missing cable of the right length halts commissioning just as reliably as a missing unit.

Which to choose

If there's no switchgear room near the feeder and the control device has to sit in shop-floor conditions, choose the ШУВ cabinet — its IP54 rating needs no extra enclosure. If the site already has an automation cabinet with a DIN rail in a clean room and cables from several feeders run there, the compact БУВ or БУВ-ш unit is usually more space- and cost-efficient, and easier to scale as the number of control points grows. See the full model lineup and specifications on the ШУВ / БУВ control devices page.

The short procedure: read the drive type and coil current from the feeder spec table; decide where the device will physically stand, in the workshop or in an electrical room; decide who sets the output — operator, plant control system or weighing controller; and answer separately whether amplitude stabilisation is needed. Four answers fix the version unambiguously. If the feeder itself is not chosen yet, start there — sizes are in the PEV feeder catalogue and drives in the VEM vibro-drives section.

Frequently asked questions

Not sure which design fits your site — send us a description of the installation conditions via the request form and we'll help you choose.