Control Techniques and Nidec Drives, New Zealand

RFQ / Control Techniques and Nidec

If your drive says Emerson on the front, it is a Control Techniques drive. The brand changed hands twice and the part numbers did not change with it, so a badge that says Control Techniques, Emerson or Nidec can be the same product.

Control Techniques drives are on a great deal of New Zealand machinery, particularly timber processing, extrusion, winding, cranes and anything with a DC motor still in service. Unidrive SP and Mentor II are the two we are asked for most, and both are out of production.

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Reference pages

Page	Covers
Unidrive SP	The SP model decode, the three Solutions Module slots, SM-Applications and where the machine program lives, SMARTCARD cloning, trip codes and the migration to Unidrive M
Mentor II DC drives	The model number is armature amps, two quadrant against four quadrant, the field circuit as half the fault list, semiconductor fuses, thyristor against commutator symptoms, and why these store well as spares
Commander SK	SmartStick and LogicStick, single phase against three phase input, the one option slot, the cL current loop trip and why one panel position keeps killing drives

The badge changed three times

Worth settling first, because it confuses part searches.

Badge	Era
Control Techniques	The original company, and the name currently in use
Emerson	The Emerson Industrial Automation period. Same products
Nidec Control Techniques	Current owner

A drive labelled Emerson Unidrive SP and one labelled Control Techniques Unidrive SP are the same drive. The model number is what matters, and it did not change.

So if a maintenance system lists an Emerson drive and the catalogue only shows Control Techniques, that is a rename rather than a different product. Send the model number.

The ranges

AC drives

Range	Position	Status
Unidrive SP	The flagship general purpose and servo drive. Huge installed base	Discontinued
Unidrive Classic	The range before SP	Long discontinued
Unidrive M	The SP successor. M100 to M900	Current
Commander SK	The small general purpose drive. Very common	Discontinued
Commander C	The Commander SK successor	Current
Commander CD and CDE	Earlier compact range	Long discontinued
Affinity	HVAC and building services drive	Discontinued
Powerdrive F300	Larger industrial drive	Current
Elevator drives	E200 and E300, plus Unidrive SP with lift software	Mixed

DC drives

Range	Notes
Mentor II	The DC drive that will not die. Still running winders, extruders and cranes here
Mentor MP	The Mentor II successor
Quantum III, Vector	Earlier DC ranges

Servo and motors

Range	Notes
Digitax ST	Compact servo drive
Digitax HD	Current compact servo
Epsilon EP	Earlier servo range
Unimotor fm and hd	Servo motors. Matched to the drive by feedback type

Unidrive SP and Mentor II are the two ranges where we do most of our work, because both are obsolete, both are still in service in quantity, and neither can be replaced without touching the machine.

Something removable holds the machine, on every range

The pattern that runs through this whole brand, and the reason so many replacement drives fail to fix anything.

Range	Parameters live on	Machine logic can live on
Unidrive SP	SMARTCARD	SM-Applications module
Commander SK	SmartStick	LogicStick
Mentor II	The drive, and its documentation	MD29 coprocessor module

On all three, the part that holds the machine is small, removable and easy to throw away with the old drive.

Two habits follow, and both are close to free:

Take a parameter copy off every running drive now, using a SMARTCARD or a SmartStick. No laptop and no software licence.

And before any drive leaves the site, look inside it. If there is a module or a stick, it comes out first.

Solutions Modules

A Unidrive SP has three option module slots and a Commander SK has one. The modules do the fieldbus, the extra I/O, the feedback and in some cases the machine program itself.

Module type	What it adds
SM-PROFIBUS-DP, SM-DeviceNet, SM-CANopen, SM-Ethernet, SM-EtherCAT	Fieldbus
SM-I/O Plus, SM-I/O 32, SM-I/O Lite	Additional digital and analogue I/O
SM-Universal Encoder Plus, SM-Encoder Plus, SM-Resolver	Position feedback
SM-Applications, SM-Applications Plus, SM-Applications Lite	A programmable motion coprocessor
SM-Keypad, SM-Keypad Plus	The display and keypad, which is also an option on SP

Modules do not cross from SP to M

Important on any migration.

Unidrive SP uses SM-prefixed Solutions Modules. Unidrive M uses a different option module family. They are not interchangeable.

So moving from SP to M means new fieldbus modules, new feedback modules and, if there is an SM-Applications program, a rewrite into the M platform's own environment.

That is why an SP to M migration is a project rather than a swap, and why a like-for-like SP is often the cheaper answer on a machine with years left in it.

The menu structure, and how to read a drive

Useful for identifying an unlabelled unit and for troubleshooting.

Menu	Covers
0	The basic set-up parameters, gathered from elsewhere
1	Speed reference
2	Ramps
3	Speed feedback and speed loop
4	Torque and current control
5	Motor control and autotune
6	Sequencer and clock
7	Analogue I/O
8	Digital I/O
10	Status and trips. The trip log lives here
11	Drive identification. Model, software version, fitted modules
12	Threshold detectors and brake control
15, 16, 17	The three option module slots, one menu each

Two practical uses

Menu 11 identifies a drive whose label has gone. Power it up and read the model, the software version and what is fitted in the slots.

Menu 10 holds the trip log. So a drive that has been tripping intermittently has already recorded what happened, and that is worth reading before ordering anything.

And the slot maps to the menu. Menu 15 is slot 1, menu 16 is slot 2, menu 17 is slot 3. That tells you which physical module a parameter belongs to.

Common trips and what they usually mean

The trip is displayed as a short code rather than a number, which is helpful once you know them.

Trip	Meaning	Usually
OI.AC	Output over current	Mechanical load, or motor data and autotune
OV	DC bus over voltage	Braking. Ramp too fast, or the resistor circuit
UV	DC bus under voltage	Supply dip or a lost phase
OI.br	Braking transistor over current	Braking resistor value or a short
It.AC	Motor overload, thermal model	Load or motor rated current setting
Oht1, Oht2, Oht3	Over temperature	Fan or airflow. Both serviceable
th	Motor thermistor	The motor, or the thermistor wiring
cL	Current loop loss on an analogue input	A 4 to 20 mA sensor or its cable
Enc trips	Encoder fault	Feedback device, cable or the feedback module
SL trips	Solutions Module fault or timeout	The module in that slot, not the drive
EEF	Parameter memory failure	Default parameters have been restored. See below
HF trips	Hardware fault	The drive itself
Et	External trip	Something the machine told the drive, not a drive fault

EEF is the one worth recognising

A parameter memory failure restores the drive to defaults. So the drive powers up, runs, and behaves nothing like it did, because every setting has gone back to factory.

That reads as a broken machine rather than a memory fault, and people replace the drive when the drive may be fine and the parameters are simply gone.

It is also the argument for a parameter copy. With a card or a stick, an EEF is a reload. Without one, it is a recommissioning job.

SL trips point at the module

A Solutions Module trip names the slot. That tells you which module is complaining, and it is frequently the module or its cabling rather than the drive.

Worth checking before condemning an obsolete drive, because modules are cheaper and easier to find.

The brake transistor is standard, not an option

Worth flagging because it differs from other brands.

On most Unidrive SP frames the braking transistor is built in, so you add an external resistor rather than specifying a brake option at order time.

That is the opposite of Danfoss, where the brake chopper is a factory-fitted option in the type code. So on a Control Techniques drive the question is whether the resistor is there and correctly rated, not whether the drive can brake.

An OI.br trip points at the resistor value or its wiring. Tell us the resistor rating and we will check it against the drive.

Autotune matters on this range

A rotating autotune measures the motor properly and a stationary one does not measure everything. On a closed loop or high performance application the difference shows up as poor torque or instability.

Autotune	Requires
Stationary	Can be done with the load coupled. Less complete
Rotating	Motor uncoupled, or free to spin. More accurate

A replacement drive that runs rough, holds poor torque at low speed or trips under load has often only had a stationary autotune. That is free to check and it is not a hardware fault.

Before ordering a replacement

Symptom	Check first
Drive running but machine behaving oddly	EEF in the trip log. Parameters may have defaulted
Trip naming a module slot	The module, not the drive
Oht trips	Fan and airflow. Fans are replaceable on the larger frames
OV on deceleration	Braking resistor and ramp time
OI.br	Braking resistor value and wiring
Encoder trips	Feedback cable and the feedback module
Runs rough after a swap	Autotune, and whether it was rotating
Machine will not sequence after a swap	SM-Applications, LogicStick or MD29. The program lived in it
DC motor will not run at all	The field circuit and its fuses
Label unreadable	Read menu 11

What to send us

The model number off the drive, whatever badge it carries.

What is in the option slots. A photo with the covers off does it.

Whether there is an SM-Applications module, a LogicStick or an MD29, and whether anyone has the program.

The trip code and the trip log from menu 10.

Whether you have a SMARTCARD or SmartStick copy of the parameters.

The braking resistor rating, if there is one.

The feedback device, on a closed loop or servo application.

The motor nameplate, on a DC machine. Armature and field both.

What we can supply

Discontinued. Unidrive SP across the frame sizes and voltage classes, Unidrive Classic, Commander SK and CD, Affinity, Mentor II, Quantum III, Digitax ST and Epsilon EP. New old stock, surplus and tested used.

Current production. Unidrive M, Commander C, Mentor MP, Digitax HD, Powerdrive F300 and Unimotor. Quoted with a delivered lead time.

Solutions Modules. Fieldbus, I/O, feedback and SM-Applications modules, which are frequently the actual requirement.

Parts. Cooling fans, SMARTCARDs, SmartSticks, LogicSticks, keypads, semiconductor fuses and braking resistors.

Used drives are powered up and tested before they ship. Where a unit has been in long storage we tell you, because the DC bus capacitors matter.

Capacitor reforming on stored drives

Applies to the AC drives, and worth knowing which ranges it does not apply to.

The DC bus capacitors in an AC drive that has sat unpowered for years need reforming before it is run at full mains. A Unidrive SP or Commander SK bought as a spare and shelved is not necessarily a working spare, and powering it up occasionally keeps it one.

Mentor II is different. It is a thyristor converter with no DC link capacitor bank, so it stores well and comes off the shelf ready to work. That makes it an unusually good long term spare, which matters on a platform this obsolete.

We buy Control Techniques

Unidrive SP and Mentor II hold real value, because the plants running them cannot buy new and the alternative is a machine rebuild.

The Solutions Modules are worth money on their own, and an SM-Applications module with a program on it is worth considerably more than the drive around it. The same goes for a LogicStick and an MD29.

So if you are stripping a machine, leave the modules in the slots, keep the keypad, keep any card or stick with the drive, and on DC keep the field controller and unblown fuses. See Sell To Us.

Common questions

Can you get a part that is not listed on your site?
Usually. The site shows what we hold, not what we can source.

My drive says Emerson. Is that the same as Control Techniques?
Yes. Same product, different badge era. Send the model number.

Can I put a Unidrive M in place of a Unidrive SP?
Functionally yes, as a project. The option modules do not carry across and an SM-Applications program has to be rewritten.

My machine runs but does not sequence since the drive was replaced.
Check the old drive for an SM-Applications module, a LogicStick or an MD29. The program was probably in it.

The drive shows EEF.
Parameter memory failure. The drive has gone back to defaults, which is why the machine is misbehaving.

My DC motor will not run.
Check the field circuit and its fuses first. A lost field stops the motor and the drive is often fine.

Do you supply used equipment?
Yes. On Unidrive SP and Mentor II it is usually the only option, and units are tested before they ship.

What is the lead time?
Ex stock items ship the next working day within New Zealand. We give you a firm lead time with the quote.

Do you quote in NZD?
Yes, in NZD including GST for New Zealand customers.

Send us your model numbers

Whatever badge it carries, the model number is what we need. And tell us what is in the option slots, because on this brand that is often the part that matters. Quotes in NZD including GST.

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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 Nidec Control Techniques or Emerson. Control Techniques, Unidrive, Commander, Mentor, Digitax, Unimotor, Affinity, Powerdrive, SMARTCARD, SmartStick and LogicStick are trademarks of Nidec Control Techniques Ltd. Emerson is a trademark of Emerson Electric Co. All trademarks, brand names and model numbers are the property of their respective owners and are used here for identification purposes only.