Danfoss VLT HVAC Drive FC-102 and AQUA Drive FC-202, New Zealand

Danfoss / VLT HVAC Drive FC-102 and AQUA Drive FC-202

An FC-102 and an FC-202 of the same rating are close to the same hardware. What you are paying for is the application software: deragging and pipe fill on the AQUA, fire mode and building protocols on the HVAC. A physically identical drive of the wrong type will run the motor and not do the job it was bought for.

These are the two Danfoss ranges we are asked for most on New Zealand infrastructure. FC-202 on water and wastewater, FC-102 on building services and process ventilation.

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Which one do you have

	FC-102 HVAC Drive	FC-202 AQUA Drive
Built for	Fans, pumps and compressors in buildings	Water and wastewater pumping
Signature functions	Fire mode, energy optimisation, scheduling, resonance skip	Deragging, pipe fill, dry run detection, flow compensation
Protocols	Building management protocols alongside the industrial ones	Industrial fieldbus and telemetry
Predecessor	VLT 6000	VLT 6000

Both replaced the VLT 6000, which is why a single legacy range maps to two current ones. Which of the two a station should get depends on whether it is a building or a pump.

The type code tells you which you have. Send it rather than the kW rating.

The AQUA functions, and why they were specified

These are the reason an FC-202 was bought instead of a general purpose drive. If the station relies on one of them, a substitute has to have it.

Deragging

The wastewater function that saves the most call-outs. The drive detects a rising load or a torque signature that suggests a clogged impeller, then runs a sequence of forward and reverse pulses to shake the rag off.

So a pump that used to clear itself and now blocks weekly may simply have had its drive replaced with something that does not derag. That presents as a pump problem and it is a drive specification problem.

Worth asking about on any wastewater station where blockage call-outs have increased.

Pipe fill mode

Fills an empty pipe slowly to avoid water hammer. On a long rising main, filling at full speed can shock the pipework and the valves.

If a station has a documented history of burst joints or valve damage and someone specified pipe fill, that is what it is doing.

Dry run and no-flow detection

Detects that the pump is running without water and stops it before the seal is destroyed. It works from the relationship between speed and power rather than needing a flow switch.

That is a protection function. A replacement drive without it leaves the pump unprotected, and the failure it prevents is expensive.

Sleep mode and flow compensation

Function	What it does
Sleep mode	Stops the pump at low demand rather than running it at minimum speed
Flow compensation	Reduces the pressure setpoint as flow falls, because friction loss falls too
End of curve detection	Detects the pump running past its curve, usually a burst or an open valve
Check valve ramp	Controls the stop so the check valve does not slam

Sleep mode and flow compensation are energy functions and they were often the justification for the drive. Losing them does not stop the station, it just quietly costs money.

The cascade controller

Important when there is more than one pump, and the most disruptive thing to get wrong.

One drive acts as the cascade master and stages the other pumps in and out to meet demand, alternating them to equalise run hours.

Consequence
The master holds the cascade configuration. The followers do not
Replacing the master without its parameter set stops the staging, and one pump ends up doing all the work
Run hour alternation resets, so wear stops being shared

So on a multi-pump station, find out which drive is the master before you replace anything. Tell us and we will flag it on the quote.

The HVAC functions

Fire mode is a life safety function

The most important thing on the FC-102 side.

Fire mode makes the drive keep running the fan through conditions that would normally trip it, so a smoke extraction or stairwell pressurisation fan continues to operate during a fire.

Point	Detail
It is configured, not automatic	A default drive does not have it set up
It usually has a dedicated input	Triggered by the fire panel
It overrides normal protection	Deliberately. The fan runs until it cannot

So a replacement drive commissioned from defaults does not provide fire mode, and the fan will trip on the fault that fire mode was there to ignore.

If the drive is on a smoke extraction or pressurisation duty, say so. That is a compliance item and the parameter set matters more than the hardware. Whether a configuration meets the building's fire engineering belongs with whoever holds that documentation.

Building management protocols

The FC-102 talks to building systems as well as industrial ones. That is a large part of why it exists as a separate product.

Support is split between what is built in and what needs an option card, and it varies by generation and by protocol. Send the type code and tell us what the BMS speaks, and we will confirm what the drive needs.

If the drive sits on a building network rather than a PLC, that is the question to settle before ordering.

Resonance skip and broken belt detection

Function	Why it was set up
Bypass frequency, resonance skip	The fan or duct resonates at a particular speed. The drive refuses to run there
Broken belt detection	Low load at speed means the belt has gone. Stops a fan running to nothing
Automatic Energy Optimisation	Trims magnetising current on a part loaded motor
Real time clock and scheduling	Timed start, stop and setback

Resonance skip is worth knowing about because the symptom of losing it is noise and vibration, not a fault. A replacement drive at defaults will happily sit at the frequency the original was told to avoid, and the plant room gets loud.

And the real time clock needs a battery. If scheduling has stopped working or the clock resets, that is a consumable rather than a drive fault.

Enclosure rating matters more on these ranges

Because of where they live.

Code	Rating	Typical location
E20	IP20	Inside a switchboard
E55	IP55	Wall mounted in a plant room or pump station
E66	IP66	Washdown, outdoor kiosk, reservoir site

An IP20 drive is not a replacement for an IP55 or IP66 one unless it is going inside an enclosure that provides the protection instead. On a reservoir kiosk or a wastewater site, the drive's own rating is usually the protection.

And conformal coating is a separate question from IP rating. A sealed enclosure keeps water out and does not stop hydrogen sulphide attacking the board. On wastewater, ask for the coated version.

The option slots are shared with the AutomationDrive

FC-102 and FC-202 use the same MCA fieldbus and MCB I/O option families as the FC-301 and FC-302. The slots and the cards are covered in detail on our AutomationDrive page.

Two that come up often on these ranges:

Option	Why here
MCB 114 sensor input	Temperature sensors for motor or process monitoring
MCB 105 relay card	Extra relay outputs for valves, alarms and pump staging
MCB 107 24 V backup	Keeps the drive on the telemetry through a supply dip. Common on remote stations

The 24 V backup is the one worth checking on a remote site. If a pump station stops reporting to SCADA every time the supply flickers, and another station does not, that option is the difference.

Where the value actually sits

Worth being direct about, because it changes what you should buy.

On these two ranges the parameter set is worth more than the drive. A commissioned FC-202 on a wastewater station carries the deragging thresholds, the pipe fill ramp, the dry run limits, the cascade staging and the protection settings for that specific station and its hydraulics.

Situation	Outcome
Identical drive plus LCP 102 parameter copy	Swap and run. Minutes
Identical drive, no backup	Recommissioning against whatever documentation exists
Different type or generation	Recommissioning, and the functions have to be reconfigured from scratch

So the cheapest thing any water authority or facilities team can do is take an LCP 102 round the site and copy the parameter set off every running drive. One panel, an afternoon, and every future failure becomes a swap.

We supply LCP 102 panels separately for exactly this.

Before ordering a replacement

Symptom	Check first
Pump blocking more often than it used to	Whether deragging is configured, or was lost in a swap
One pump doing all the work on a multi-pump station	The cascade master and its alternation
Plant room noisy at one particular speed	Resonance skip, lost at defaults
Smoke extraction fan trips instead of running	Fire mode configuration
Scheduling stopped or clock resetting	The real time clock battery
Drive drops off telemetry on every supply dip	MCB 107 24 V backup
Board corroded on a wastewater site	Whether the original was conformal coated
Overtemperature in a sealed kiosk	Cooling fan, filter and the kiosk itself

What to send us

The full type code. It carries the range, power, voltage, IP rating, filter class, brake and coating.

Whether it is FC-102 or FC-202. Same hardware family, different application software.

What the drive is doing. Wastewater pump, rising main, smoke extraction, chilled water. That tells us which functions matter.

Whether it is a cascade master.

Whether the duty is fire related.

Whether the site is wet, corrosive or outdoors, for IP rating and coating.

What is in the option slots.

Whether you have a parameter backup.

What we can supply

Drives. FC-102 and FC-202 across the power ratings and voltage classes, in IP20, IP55 and IP66, coated and uncoated, braked and unbraked.

The related ranges. FC-101 HVAC Basic and FC-103 Refrigeration, which share the platform.

Option cards. MCA fieldbus, MCB I/O, relay, sensor and 24 V backup options.

Panels. LCP 101 and LCP 102, and blanking plates.

Parts. Cooling fans, filters, real time clock batteries and braking resistors.

Where a build is no longer available new we supply surplus and tested used, which keeps a station on its original parameter set.

We buy FC-102 and FC-202

Both ranges hold value, and IP55 and IP66 units more so because they are what water sites actually need. Coated units are worth more again.

If a station is being upgraded, keep the LCP with the drive and the option cards in their slots, and tell us if a drive came out of wastewater so we can describe the coating correctly. 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.

Can I use an FC-302 instead of an FC-202?
It will run the pump. It does not have deragging, pipe fill, dry run detection or the cascade controller. On a wastewater station that matters.

Can I use an FC-202 instead of an FC-102?
For a straightforward fan or pump, usually yes. Not if the duty needs fire mode or a building protocol.

My pump keeps blocking since the drive was replaced.
Check whether deragging is configured. That is the most common version of this question.

Is IP66 worth it?
On an outdoor kiosk or a washdown area, yes. It is also not a substitute for conformal coating on wastewater.

Do you supply used equipment?
Yes, where new is not available. Used drives are powered up and 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 type codes

Tell us what the drive is doing as well as what it is. On these two ranges the application decides the product. 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 Danfoss. Danfoss, VLT, HVAC Drive and AQUA Drive are trademarks of Danfoss A/S. BACnet is a trademark of ASHRAE. All trademarks, brand names and type codes are the property of their respective owners and are used here for identification purposes only.