In short. A permanent-magnet synchronous motor is brought up under drive control rather than connected across the line, which is why the starting current of a drive-fed compressor is a different quantity from the inrush of a direct-on-line motor. The catalog publishes a starting-current field and a VFD input of 380 VAC ±10 per cent, but it does not publish the conditions behind the current figure — so it indicates intent, and the conditions have to be asked for before anything is sized on it.
Where the old number came from
Anyone who has specified motors has a rule of thumb about starting current, and it comes from induction motors connected directly to the supply. Started that way, a motor draws a large multiple of its running current for a short period, and that inrush is what sets a great deal of the electrical design around it: supply capacity, protection settings, cable sizing, and the voltage dip the rest of the site has to tolerate.
The rule of thumb is useful precisely because direct-on-line starting is simple and its behaviour is well understood. It is also the reason the number is so often carried into conversations where it no longer applies.
What a drive changes
The S series publishes a permanent-magnet synchronous motor. A machine of that type is not connected to a fixed-frequency supply and expected to start; it is brought up under the control of a drive, and the drive decides the ramp.
That changes the shape of the problem. Instead of a fixed inrush determined by motor and supply impedance, the current during starting is a controlled quantity — bounded by what the drive is configured and rated to deliver. This is why a drive-fed machine can publish a starting-current field that would be implausible for a direct-on-line motor of similar power: it is not the same measurement.
It also means the motor and the drive stop being separable choices. The published VFD table states an input of 380 VAC ±10 per cent at 50/60 Hz, and that input is part of the compressor's electrical specification, not a downstream detail.
Reading the published field
The site publishes a starting-current field of 2 A, and it is labelled as a catalog field. It is worth saying plainly what that does and does not settle.
What it indicates is the intent of the architecture: a drive-fed permanent-magnet machine is designed so that starting is a controlled event rather than a supply-sizing event. That is a real and useful property, and it is why this class of machine is often attractive where supply capacity or voltage dip is constrained.
What the field does not state is the conditions it was obtained under — which model, at what load, with what drive configuration, measured how. Without those, it cannot be carried into a supply calculation. The rest of this site takes the same position on published figures, and it applies here: the number indicates a design intent, and the conditions have to be requested before it becomes an engineering input.
The same caution on efficiency
The VFD table publishes an efficiency field of ≥97 per cent and states, in the same entry, that the test conditions are not given. That honesty is worth using rather than skipping past.
Drive efficiency varies with load and switching frequency, and a figure quoted without a load point is not comparable to another figure quoted without one. More importantly, drive efficiency is not motor efficiency, and neither is the efficiency of the compressor as installed. Three different numbers, three different boundaries, and only one of them is in this table.
What to put in the brief
Because the drive and the motor are selected together, the electrical section of an application brief carries more weight here than it would for a line-started machine. Five things are worth stating up front.
The supply voltage, frequency and tolerance the site actually provides, checked against the published 380 VAC ±10 per cent. The power architecture behind it, including whether a transformer sits in the path. Any harmonic limit the site or the local code imposes, since that is resolved with filtering that has to be specified rather than added later. The restart behaviour expected after a supply interruption. And the control interface — the table publishes RS485 Modbus and CAN, and whether that matches the chiller controller already chosen decides whether a gateway becomes part of the design.
None of these are difficult to answer. They are simply easier to answer before a panel layout exists than after.
Source basis
Published ChillerRotor catalog fields: permanent-magnet synchronous motor for the S series (CAT-202607-P06), the starting-current field shown on the home page, and the high-power VFD table (CAT-202607-P12) for input voltage, efficiency and communications. Neither the starting-current field nor the efficiency field states its test conditions, and this guide does not supply them.
Independent standards and regulation
These are external to this catalog and were checked against the issuing body before being cited. They define the method or the rule; they do not validate any value published on this site.
- IEC 61800-2:2021 — Rating specifications for adjustable speed AC power drive systems. It treats the semiconductor conversion, its control and the motor as one system, which is the reason a drive-fed starting current is a configured and rated quantity rather than a property of the machine.
Catalog values describe the documents this website works from. They are not a performance guarantee for a delivered unit, and project values are confirmed in writing. Read the source policy