Control Techniques Commander SK, New Zealand

Two small plug-in sticks do the work that a memory card and a PLC do elsewhere. The SmartStick holds the parameters and the LogicStick holds machine logic. Both are removable, both are easy to throw away with the old drive, and one of them may be the only copy of how the machine runs.

Commander SK is the Control Techniques small general purpose drive. It is discontinued and it is on an enormous number of conveyors, fans, pumps and small machines across New Zealand.

Request a quote

Where it sits in the range

Drive	Position
Commander SK	Simple open loop drive. Speed control, minimal configuration
Unidrive SP	Closed loop, servo, motion, three option slots
Commander C	The current successor to SK
Commander CD, CDE	The range before SK

Commander SK is deliberately simple. If a machine needs encoder feedback, positioning or a servo motor, it was never an SK, and a like-for-like replacement is the only sensible route.

Frame size and the model number

Commander SK comes in frame sizes, and the frame decides the physical fit as much as the rating.

Frame	Notes
Size A	The smallest. Fractional and small kW ratings
Size B, C	Mid range
Size D, E	The larger units

The digits in the model number carry the voltage class and the current or power rating. Single phase and three phase input variants exist at the smaller sizes, and they are not the same part.

Send the whole label rather than the kW figure. Single phase against three phase input, and 200 V against 400 V class, are both in there and both matter.

Single phase input is a real variant

Worth checking, because it is common on small machines and easy to get wrong.

A single phase input drive still produces a three phase output to the motor. So a three phase motor on a single phase supply is normal and correct.

Fitting a three phase input drive onto a single phase supply does not work, and fitting a single phase input drive where three phase is available wastes capacity. Check the incoming supply, not just the motor.

The SmartStick

The Commander SK equivalent of a memory card, and the cheapest thing you can do on this drive.

A SmartStick clones a full parameter set from one drive to another. Plug it into the running drive, copy up, plug it into the replacement, copy down.

Situation	Outcome
Stick copy exists	Fit the drive, load, run. Minutes
No copy	Parameters re-entered by hand, if anyone recorded them
A row of identical conveyors	One stick commissions all of them

On a site with a dozen identical SK drives this is the single highest value habit available. One stick, an afternoon, and every future failure is a swap.

We supply SmartSticks separately.

The LogicStick, and the trap in it

The one that catches people, because it looks like an accessory and behaves like a PLC.

A LogicStick adds programmable logic to the drive, so simple machine sequencing can run inside the SK with no PLC anywhere.

Situation	Outcome
Drive replaced, LogicStick moved across	The logic comes with it
Stick scrapped with the old drive	The machine's logic is gone
New drive fitted without it	Motor runs, machine does not sequence

So a small machine with no visible PLC and a drive doing more than speed control probably has a LogicStick in it. That is a very small part carrying the whole control scheme.

Look in the drive before it goes in the skip. Both sticks are physically small and both are worth keeping.

One option module slot, so you choose

A real constraint compared with the Unidrive SP.

Commander SK takes a single Solutions Module. The SP takes three.

Module	Adds
SM-PROFIBUS-DP	PROFIBUS DP
SM-DeviceNet	DeviceNet
SM-CANopen	CANopen
SM-Ethernet	Ethernet based protocols
SM-I/O Lite	Additional I/O

So you get fieldbus or extra I/O, not both. If a machine needs a network and more terminals, that decision was made at build time and the alternative was a bigger drive.

Modbus RTU over the drive's own serial port needs no module, so an SK on plain serial has an empty slot, correctly.

The module does not come with a replacement drive. Move it across or put it on the order.

The display is built in

Different from the Unidrive SP, where the keypad is an ordered option.

Commander SK has an integral display and buttons, so a bare drive can be set up and read without buying anything else.

That makes it a straightforward drive to commission, and it means a blank or dead display on an SK is a fault rather than a missing option.

Common trips

Commander SK uses the same short trip codes as the rest of the range.

Trip	Meaning	Usually
OI.AC	Output over current	Mechanical load, or motor rated current set wrongly
OV	DC bus over voltage	Deceleration too fast, or no braking resistor
UV	DC bus under voltage	Supply dip or a lost phase
It.AC	Motor thermal overload	Load, or the motor current parameter
Oht	Over temperature	Airflow, and the panel ambient
th	Motor thermistor	The motor or its wiring
cL	Current loop loss on an analogue input	A 4 to 20 mA signal has gone. Sensor or cable
EEF	Parameter memory failure	Defaults restored. The drive may be fine
Et	External trip	The machine told the drive to stop

Two worth expanding

EEF restores factory defaults, so the drive powers up and runs and the machine behaves nothing like it should. That reads as a dead machine and the drive may be perfectly serviceable. With a SmartStick copy it is a reload.

cL is a lost 4 to 20 mA signal, not a drive fault. On a pump or fan following a pressure or level transmitter, that trip points at the transmitter or its cable.

Panel temperature is the quiet killer

Worth its own note on this drive, because of where SKs get installed.

Small drives get fitted into small enclosures with no ventilation, often as an afterthought on an existing machine. The drive then runs hot for its whole life and fails early.

Sign	What it means
One drive of several keeps failing	That enclosure, not that model
Oht trips in summer only	Ambient, not the drive
Drives failing in a small sealed box	No airflow

So if one location eats drives and identical ones elsewhere last for years, measure inside the enclosure before ordering another. The answer is usually ventilation.

Same pattern as the panel derating issue on our Omron page. It applies to any small component in a closed box.

Before ordering a replacement

Symptom	Check first
Drive runs, machine misbehaves	EEF. Parameters may have defaulted
Machine will not sequence after a swap	The LogicStick from the old drive
cL trip	The transmitter and its 4 to 20 mA loop
Oht trips	Enclosure ventilation and ambient
OV on stopping	Deceleration ramp, and whether a resistor is fitted
Fieldbus dead after a swap	The Solutions Module. It does not come with the drive
Same location keeps failing drives	The panel, not the model

What to send us

The full model number off the label. It carries frame, voltage class and rating.

Whether the supply is single phase or three phase.

Whether there is a SmartStick or a LogicStick in the drive.

What is in the option slot.

The trip code.

Whether a braking resistor is fitted.

What we can supply

Drives. Commander SK across the frame sizes and voltage classes, single and three phase input. New old stock, surplus and tested used.

Sticks. SmartSticks and LogicSticks, supplied separately.

Modules. Fieldbus and I/O Solutions Modules for SK.

The successor. Commander C, where a like-for-like SK is not the right answer.

Earlier ranges. Commander CD and CDE.

Used drives are powered up and tested before they ship, and where a unit has been in long storage we say so because the DC bus capacitors need reforming.

These are cheap spares to hold

Commander SK is small, inexpensive and used in quantity, which makes it the easiest platform on this brand to be properly covered on.

Item	Why
One SmartStick, and a copy of every drive	Free to make and it turns every failure into a swap
One drive per rating you run	Supply is finite and shrinking
A spare LogicStick, where one is fitted	It carries the machine logic

The stick copies are the job to do this week. A row of conveyor drives with no parameter backup is a day of downtime waiting to happen, and the fix costs almost nothing.

We buy Commander SK

SK drives resell readily because the machines running them are everywhere and the range is discontinued.

Keep the sticks in the drive and any Solutions Module in the slot. A LogicStick is small, easy to lose and worth real money to the next plant. 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.

What is the difference between a SmartStick and a LogicStick?
The SmartStick copies parameters. The LogicStick adds programmable logic and may hold the machine's control scheme.

Can I run a three phase motor from a single phase supply?
Yes, with a single phase input drive. Check the incoming supply as well as the motor.

My machine will not sequence since the drive was changed.
Look for a LogicStick in the old drive.

The drive shows cL.
The 4 to 20 mA input has lost its signal. Check the transmitter and cable, not the drive.

One position keeps killing drives.
Measure the enclosure temperature. It is almost always ventilation rather than the model.

Do you supply used equipment?
Yes, where new is not available, tested and clearly described.

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

Check the drive for a SmartStick and a LogicStick before it comes off the wall. They are small, they are easy to bin, and one of them may be the only record of how the machine runs. 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 Nidec Control Techniques or Emerson. Control Techniques, Commander, SmartStick, LogicStick and Solutions Module are trademarks of Nidec Control Techniques Ltd. PROFIBUS is a trademark of PROFIBUS Nutzerorganisation. All trademarks, brand names and model numbers are the property of their respective owners and are used here for identification purposes only.