SEW-Eurodrive / MOVIMOT

SEW says it directly: do not use a conventional earth-leakage circuit breaker as a protective device on MOVIMOT. If a plant has fitted a standard RCD to a decentralised drive circuit, that is worth raising.

MOVIMOT is the SEW gearmotor with the inverter built onto it. On conveyors and materials handling across New Zealand, and the reason a lot of plant has no drive section in the panel.

Reading a MOVIMOT type code

Take MM15D-503-00.

The power digits

The voltage group

The generation letter matters too. Earlier units are C series, as in MM03C-503-00, and the current range is D.

Two frame sizes

So a step up in power can be a step up in frame. Worth checking if the unit sits in a confined space on the machine.

Mounted on the motor, or close to it

Two arrangements, and they carry different type designations.

The extended code carries the connection box, the options fitted and the connection design. APG4, ALA4 and ASB4 are connection designs on the MOVIMOT side.

So if a nameplate has slashes in it, send the whole string. The base code alone does not identify the unit.

The hybrid cable must be SEW's own

Stated plainly and worth taking seriously.

Where a MOVIMOT is mounted close to the motor rather than on it, the connection is made with a pre-fabricated hybrid cable, and SEW instructs that only SEW-EURODRIVE hybrid cables be used.

A hybrid cable carries the motor power and the brake and thermal circuits in one assembly, pre-terminated to match the connection design at both ends.

Confirmed part numbers include 0 817 948 4 and 0 816 208 5, and the correct one depends on the connection design at each end.

So a replacement cable is not a generic motor lead. Tell us the designs at both ends and we will match it.

MOVIMOT needs a 24 V supply

The thing that stops a newly fitted unit doing anything.

SEW specifies supplying MOVIMOT either via external 24 V DC, or via the MLU..A or MLG..A options.

So mains alone is not enough. If a MOVIMOT has been fitted and is completely dead, check the 24 V before anything else.

SEW notes the MLU13A is generally installed in the modular terminal box at the factory, so it may already be there.

Binary control, and what the terminals do

The simplest MOVIMOT arrangement, and the most common on a conveyor.

So a two-speed conveyor with no analog reference is doing it with one terminal. The speeds are set physically on the unit: potentiometer f1 and switch f2, with t1 setting the ramp.

SEW notes CW/stop or CCW/stop can be used for jog mode.

The physical settings are on the unit, not in a file

Which is both the strength and the trap of MOVIMOT.

A replacement MOVIMOT arrives with its potentiometer and switches at default. There is no parameter file to load, because there are no parameters in the usual sense.

So photograph the potentiometer position and the switch settings before removing the old unit. That is the entire configuration and it exists nowhere else.

Note the screw plugs over the f1 potentiometer and the X50 connection tighten to 2.5 Nm.

In bus mode the pot is ignored, but the DIP switches are not

A distinction that causes real confusion.

SEW states that when the drive is controlled over the network, potentiometer f1 and switches f2 and t1 are deactivated and their settings are ignored, while the setting of the DIP switches continues to be read.

So on a networked MOVIMOT the pot position tells you nothing, and the DIP switches still matter.

When replacing one, record the DIP switches regardless of how the drive is controlled. They carry the address, the mode and the switching frequency.

DIP switch S1/7 is the low noise setting

Specific and useful.

With S1/7 set to ON, MOVIMOT operates at a 16 kHz PWM frequency for low noise, and switches back in steps to lower switching frequencies depending on heatsink temperature and inverter load.

So a quiet MOVIMOT that gets noisier as it warms up is not faulting. It is derating its switching frequency as designed.

Worth knowing before someone chases a noise that appears only on a hot afternoon.

Only one bus master

SEW is emphatic about this.

With a bus master PLC, an MLG..A, MBG11A or MWA21A option, or an MF or MQ fieldbus interface, the instruction is: connect one bus master only.

So a diagnostic unit is not something to leave connected to a running multi-drop bus. It is a commissioning and fault-finding tool on a single unit.

If a line of MOVIMOTs has become erratic and someone has left a diagnostic unit plugged in, that is worth checking.

The X50 diagnostic interface

Where to connect when a unit is misbehaving.

The X50 diagnostics interface is on top of the MOVIMOT inverter.

The DBG keypad is the same one used on MOVIDRIVE and MOVITRAC, so one keypad plus a DKG60B adapter covers the whole SEW range on a site.

That is worth knowing before someone buys a separate tool for the decentralised drives.

Options fitted at the factory

Some MOVIMOT options are not straightforward to retrofit.

SEW notes that the URM, BEM and BES options are installed in the connection box at the factory, and directs enquiries about retrofitting to SEW service.

So a MOVIMOT with a brake needs the right rectifier option in the box. A unit ordered without one is not a drop-in for a braked drive.

Check the extended type designation, which carries the options.

Motor protection needs a TH

Worth stating because it is a specific instruction.

SEW states that to ensure motor protection, a TH bimetallic thermostat must be used.

An open circuit on the thermal input reads as an over-temperature. If a MOVIMOT trips on motor temperature and the motor is cold, check the thermostat and its wiring before the drive.

Do not use a conventional RCD

Putting SEW's instruction plainly, because it matters.

Do not use a conventional earth-leakage circuit breaker as a protective device.

For line protection SEW specifies NH melting fuses or circuit breakers on F11, F12 and F13, sized per the documentation.

This is a design matter for your electrician rather than a parts matter, but it is worth knowing the manufacturer says it, particularly on a decentralised installation where drives are scattered across a plant on shared circuits.

Hot surfaces

SEW carries a burns warning on MOVIMOT surfaces and external options, particularly braking resistors.

A decentralised drive sits out on the machine where people work, rather than behind a cabinet door. That changes who is likely to touch it.

Assembly torques

Useful when refitting, and easy to get wrong on a plastic connection box.

Diagonally across matters on the inverter screws, because the seal has to compress evenly. A unit that leaks after a repair is often a tightening sequence problem.

Note SEW flags that on some mounting arrangements screws are not included in the scope of delivery.

What to send us

The full type designation, including everything after any slash. The extended code carries the connection box, options and connection design.

Whether it is mounted on the motor or close to it.

A photo of the potentiometer and switch positions, if the unit still has them set.

A photo of the DIP switches.

The motor and gear unit nameplate.

Whether there is a brake, since that decides the rectifier option.

Before ordering a replacement

Check the 24 V supply. A completely dead MOVIMOT is often a missing 24 V, not a failed drive.

Check the TH thermostat if it trips on motor temperature with a cold motor.

Check whether a diagnostic unit has been left connected to a multi-drop bus.

Check S1/7 if the noise level has changed. It derates by design.

Record the pot, switch and DIP settings before removal. They are the configuration and they exist nowhere else.

What we can supply

Current production. MOVIMOT D series across the power range and both voltage groups, MLU and MLG supply options, MF and MQ fieldbus interfaces, MBG11A and MWA21A, DKG60B adapters, hybrid cables, connection boxes and brake options. Quoted with a delivered lead time.

Discontinued. MOVIMOT C series and earlier. Surplus and tested used, which keeps an existing installation on its original mounting and cabling.

Hybrid cables separately. Frequently the fault on a drive mounted close to the motor, because the cable is out in the machine taking abuse.

The cable is worth suspecting

Worth its own note on decentralised installations.

A hybrid cable runs out on the machine, through cable chains and past moving parts. It carries power, brake and thermal circuits in one assembly.

So a fault that looks like a drive or a motor is often the cable, and a break in the thermal core reads as a motor over-temperature.

Before condemning a MOVIMOT on a close-mounted installation, check the cable.

We buy SEW MOVIMOT

MOVIMOT units hold value, and complete gearmotor assemblies more so.

Keep hybrid cables and connection boxes with the units. See Sell To Us.

Related

SEW-Eurodrive overview and MOVITRAC B.

For decentralised drives from other brands see Lenze motec and Beckhoff AMP8000.

Send us your type designations

Send everything after the slashes, and photograph the switch settings before you remove the unit. Quotes in NZD including GST.

Request a quote

Industech is an independent supplier of new, surplus and used industrial automation equipment. We are not an authorised distributor of, approved by, sanctioned by, or affiliated with SEW-Eurodrive. SEW-Eurodrive, MOVIMOT, MOVIDRIVE, MOVITRAC and MOVIGEAR are trademarks of SEW-Eurodrive GmbH & Co KG. AS-Interface is a trademark of AS-International Association. All trademarks, brand names and part numbers are the property of their respective owners and are used here for identification purposes only. Information on this page is for identification and does not constitute electrical design or safety advice.