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134U3874 Danfoss VLT HVAC Drive 2.2 kW/3.0HP 380-480VAC IP55
Danfoss 134U3874 VLT HVAC Drive FC 102, a 2.2 kW three-phase AC variable frequency drive with IP55 Type 12 backplate enclosure, Modbus TCP MCA 122, MCB-101 general purpose I/O, coated PCB, graphical local control panel and RFI Class A1/B C1 filter for HVAC motor control applications.
£871.75
Danfoss 134U3874 at a glance
The Danfoss 134U3874 is a 2.2 kW VLT HVAC Drive FC 102 for 3 × 380–480 V AC supplies, made for the fans, pumps and compressors in building services. It is a frame A5, IP55 / UL Type 12 with backplate unit, built for wall mounting in plant rooms without a separate enclosure.
This configuration has RFI class A1/B (C1) with reduced motor cable length, no brake chopper, a graphical LCP 102 control panel, and a Modbus TCP MCA 122 fieldbus card. The full type code is decoded alongside the FAQs.
Sizing and installation
- Enclosure: IP55 / UL Type 12 with backplate — built for wall mounting in plant rooms without a separate enclosure.
- EMC: RFI class A1/B (C1) is met only with a reduced screened motor cable length. Check the maximum length for this frame in the Danfoss FC 102 Design Guide (Technical Documents tab); for longer runs, ask us about an H2 (A2/C3) variant.
FC 102 features for HVAC
- Built-in RS-485 protocols: Danfoss FC, Modbus RTU, BACnet MS/TP, Metasys N2 and FLN Apogee — connects to most building management systems without an option card.
- Fire Mode keeps the drive running during an emergency, for example to keep smoke-extract fans turning.
- Automatic Energy Optimisation (AEO) cuts motor losses at part load — Danfoss quotes a further 5–15% saving.
- Pump and fan functions: sleep mode, dry-pump, end-of-curve and broken-belt detection, plus a built-in cascade controller for pump sets.
- Built-in DC coils limit mains harmonics (EN 61000-3-12).
- Smart Logic Controller for simple sequencing without a PLC.
Where the energy saving comes from
Centrifugal fans and pumps follow the affinity laws: absorbed power falls with the cube of speed. Running at 80% speed needs roughly half the power of full speed (0.8³ ≈ 0.51, before motor and drive losses) — which is why speed control pays back faster on fans and pumps than almost any other load.
Other sizes and enclosures
Same configuration, different power
This drive2.2 kWDanfoss 134U3874IP55 / UL Type 12 with backplate · frame A5
Larger3 kWDanfoss 134U3875IP55 / UL Type 12 with backplate · frame A5View drive →
Same 2.2 kW rating, other enclosures
This driveIP55Danfoss 134U3874IP55 / UL Type 12 with backplate
EnclosureIP20Danfoss 131B5470IP20 / chassisView drive →
EnclosureIP66Danfoss 131B9297IP66 / UL Type 4XView drive →
Typical applications
✓ Supply and extract fans in air-handling units
✓ Chilled- and hot-water circulation pumps
✓ Cooling towers and condenser fans
✓ Booster sets and multi-pump stations
✓ Ventilation and smoke-extract systems
Technical Specifications
Tick the specs you need, then view products that match.
| Power | 2.2 kW | |
|---|---|---|
| Voltage | 480 V | |
| Phase | Three Phase | |
| IP Rating | IP55 | |
| EMC Filter | Commercial | |
| Series | VLT® HVAC Drive FC 102 | |
| Part Number | 134U3874 | |
| Model Code | FC-102P2K2T4P55H3XGCXXXSXXXXAQBKCXXXXDX | |
| Product type | AC variable frequency drive | |
| Rated output power | 2.2 kW | |
| Horsepower rating | 3.0 HP | |
| Input voltage | 380-480 V AC | |
| Input phases | Three-phase | |
| Protection rating | IP55 / Type 12 Backplate | |
| RFI filter | Class A1/B (C1) | |
| Brake chopper | No brake chopper | |
| Communication option | Modbus TCP MCA 122 | |
| I/O option | MCB-101 General Purpose I/O | |
| Control panel | Graphical Local Control Panel | |
| PCB coating | Coated PCB | |
| Mains option | No mains option | |
| Frame size | A5 | |
| Dimensions (H × W × D) | approx. 420 × 242 × 200 mm | |
| Weight | approx. 12.31 kg | |
| EAN | 5710107999002 |
Frequently asked questions
What is the maximum motor cable length with this RFI filter?
The 134U3874 has the H3 filter: RFI class A1/B (C1) with a reduced motor cable length. The exact limit for this frame is in the Danfoss VLT HVAC Drive FC 102 Design Guide (see Technical Documents). If your screened cable run is longer, contact us and we will suggest an alternative.
Which communication protocols does it support?
This unit is fitted with a Modbus TCP MCA 122 card, in addition to the built-in RS-485 protocols: Danfoss FC, Modbus RTU, BACnet MS/TP, Metasys N2 and FLN Apogee.
Can this drive be wall mounted without a panel?
Yes. The IP55 / UL Type 12 with backplate enclosure is designed for direct mounting.
Type code decoded
FC-102P2K2T4P55H3XGCXXXSXXXXAQBKCXXXXDX
G fitted / defines this unit X not fitted / standard
| Product series Position 1–6 | VLT HVAC Drive FC 102 | FC-102 |
|---|---|---|
| Power size Position 7–10 | 2.2 kW | P2K2 |
| Mains voltage Position 11–12 | 3 × 380–480 V AC | T4 |
| Enclosure Position 13–15 | IP55 / UL Type 12 with backplate | P55 |
| RFI filter Position 16–17 | RFI class A1/B (C1) with reduced motor cable length | H3 |
| Brake / Safe Stop Position 18 | No brake chopper | X |
| Local control panel Position 19 | Graphical LCP 102 | G |
| PCB coating Position 20 | Conformal-coated PCBs | C |
| Mains option Position 21 | No mains option | X |
| Adaptation A Position 22 | Standard cable entries | X |
| Adaptation B Position 23 | Standard | X |
| Software release Position 24–27 | Latest standard release | SXXX |
| Software language Position 28 | Standard language package | X |
| A option (fieldbus) Position 29–30 | Modbus TCP MCA 122 | AQ |
| B option (I/O) Position 31–32 | MCB 101 general-purpose I/O | BK |
| C0 option Position 33–34 | No C0 option | CX |
| C1 option Position 35 | No C1 option | X |
| C option software Position 36–37 | None | XX |
| D option Position 38–39 | No D option | DX |
