Sanyo C-R224H3R Rotary Compressor: R22, 200-220 V Three Phase, and the Two Nomenclatures Behind the Code

The C-R224H3R is a Sanyo hermetic rotary compressor for air-conditioning duty, built for an R22 circuit on a 200-220 V three-phase supply, and sold as a 3 HP class unit by the retail listings that carry it. What makes it worth a separate article is not the compressor but the code. Sanyo printed two model-code rules for this range, one after the other, and the same three characters mean different things in each. Under the later rule the three-digit block is a displacement multiplied by ten, which would put this model at 22.4 cm3/rev. The catalogue's own legacy rows, printed in the same document, sit at about twice that figure for the same block. The difference is not a rounding error, and it is the reason this article gives the block as a class marker and sends the reader to the nameplate for the number.

Key facts at a glance

The upper half of that table is attested across at least two independent sources. The lower half is not attested at all, and this article does not fill it. Where a neighbouring row is quoted, it is labelled with its own model number, because a neighbour is a neighbour, not this machine.

What does the designation actually decode to?

Sanyo printed a model code rule in the 2024 rotary catalogue, and it is worth reading literally before reading it sceptically. The rule is given in two forms, and the second is the one that matters here:

The two rules are not interchangeable, and a model string that follows one can be misread by a buyer who assumes the other. The refrigerant legend is printed alongside: 1 is R410A, 2 is R22, 7 is R407C, 4 is R404A and 3 is R32. The use letters are printed too: H is high back pressure, M medium, L low and E extra low.

Read against nomenclature 2, C-R224H3R gives a 224 block as a displacement of 22.4 cm3/rev, an H for high back pressure, a 3 that the legend assigns to R32, and a tail that is not a cooling-method letter. Read against nomenclature 1, the block is a motor output figure and the 3 sits where a voltage distinction belongs. Neither reading survives contact with the rows intact: the displacement reading collides with the printed legacy rows, and the refrigerant digit collides with the parts catalogue.

A power reading is not absurd on its face. If the block counts motor output in the units the rule prints, 224 falls inside the small-rotary range, which is the size class the retail listings are describing when they call this a 3 HP machine. That is a consistency check and not a rating: Sanyo prints no row for this designation, and the horse-power figure comes from resellers rather than from the manufacturer.

Why is the block not 22.4 cm3/rev?

Because the catalogue contradicts its own rule in the rows it prints. Five models in the legacy C-R series, all with the same string shape as this one, print a displacement roughly twice what the block divided by ten would give:

Five rows, five different blocks, and a ratio that drifts upward from 2.08 to 2.25. This is not a conversion factor that can be applied with confidence, and it is not a coincidence either: the whole run of legacy models sits near double the block value.

One row breaks even that pattern. C-R220L4AF, in the same catalogue and the same R404A section, prints 22.0 cm3/rev for a block of 220, which is exactly the block divided by ten and half of what its neighbours suggest. A block of 224 therefore maps to about 22 cc if it follows C-R220L4AF and about 48 cc if it follows C-R223L3C, and those two answers differ by more than a factor of two.

That is the whole argument for leaving the displacement blank. A number chosen from the block would be a guess dressed as a specification, and the two candidate answers are far enough apart that a system built on the wrong one would be wrong at the condenser, not at the third decimal place.

Which refrigerant is it, R22 or R32?

The parts catalogue that lists this model states R22, three phase, 200-220 V AC, and names the build as a Kanto Seiki variant. Two retail listings agree on the electrical side, and one of them states air conditioning explicitly. That is a consistent, cross-source picture.

The code, however, points somewhere else. Under the printed legend the digit after the use letter gives the refrigerant, and 3 is R32. A sibling with 2 in that position, C-RHV195H2NA, is printed as R22; the same frame with 7 in that position, C-RHV195H7NA, is printed as R407C with the same 19.5 cc displacement. The digit does discriminate, and 3 does not mean R22 in the current rule.

Two readings therefore exist, and both have a basis:

Reading A is used as the working assumption in this article because it names the model rather than inferring from a position, and because the equipment this compressor was built into, on a 200-220 V three-phase Japanese supply, was overwhelmingly R22. Reading B is not dismissed: the same character position is genuinely load-bearing on the current models, and a legacy string may be carrying an older convention where that digit marked the voltage class instead.

The practical instruction is short. Refrigerant and phase come off the nameplate. R22 and R32 are not interchangeable, they do not share oil, and a compressor ordered on the wrong reading cannot be recovered at commissioning.

What does high back pressure mean for the application?

Back pressure maps onto the evaporating temperature band the machine is built for. High back pressure is the air-conditioning band, above freezing. Low back pressure is the freezing band. The catalogue prints the split as a letter in every model string, and prints rows for each band in separate tables, so the classification is not a marketing label.

The consequence for a buyer is what happens when the band is exceeded. A high-back-pressure rotary run at deep-freezing evaporating temperatures overheats, because the returning gas is too thin to carry heat away from the motor. A refrigeration compressor designed for that band has a larger displacement for the same cooling duty, which is exactly why the same class number appears with very different displacements in the two sections. C-R223L3C prints 48.6 cm3/rev for low back pressure, and C-R223L8C prints the same figure in the same table; C-RN223H3C, the same 223 class in the air-conditioning section, prints 10,100 W of cooling capacity at 3,570 W input and a coefficient of performance of 2.83, and needs no displacement figure to make the point that the duty is different.

Do not read those two rows as this model's performance. They are different designations for different duties. They are quoted because they show the scale of what changes when the band changes.

Why does the 200-220 V three-phase supply matter?

A 200-220 V three-phase supply is the commercial wiring standard in Japan and in several Asian markets, and it is the reason this compressor exists in this form rather than as a single-phase unit. At the cooling duties this frame covers, three-phase input keeps the current per conductor low enough for standard commercial wiring and avoids the starting-current problem that large single-phase compressors create on a weak supply.

The voltage is also the one field where the reseller data and the code agree, which is a useful check on the whole reading. The legacy rows in the refrigeration catalogue put the 3 variant on 200 V and the 8 variant on 380 V: C-RHN153L3A and C-RHN153L8A are the same 32.2 cm3/rev compressor on different supplies. The model string here carries 3 in the same position, and the resellers independently print 200-220 V. The nearest printed row in the same size class is C-RN223L3A, which is the row to compare against when the duty band is in question.

The commercial reason this configuration exists at all is the growth of air-conditioning demand, for which the International Energy Agency's Future of Cooling report remains the standard reference on scale.

How should a buyer specify this model?

Steps 4, 5 and 7 are the ones that distinguish this model from a commodity rotary. Step 7 is the one buyers most often miss: a parts catalogue lists C-R224H3R and C-R224H3U as the same Sanyo rotary on the same supply and the same refrigerant, differing only in the tail and in the customer named against it. That is a build difference, not a labelling difference.

Which references frame this class of machine?

Seven references frame the specification work. EN 12900 is the European standard for rating positive displacement refrigerant compressors, and its function is to make a capacity figure comparable by fixing the conditions of measurement; a model without a published row cannot be checked against it at all. Regulation (EU) 2024/573 governs fluorinated greenhouse gases and attaches obligations to equipment and charge rather than to the compressor alone, which is why an R22 machine in service now raises a different question from the one it raised when it was built. The ISO committee responsible for testing and rating of refrigerant compressors maintains the international counterpart of that rating framework. For the brand itself, the Panasonic global site is the corporate starting point, since Sanyo Electric has been part of Panasonic since 2011 and the compressor line moved with it. The manufacturer's own catalogue is the document that carries the two nomenclature rules quoted above, and it is the only place where the conflict between them is visible. Within the supplier's own range, the rotary compressor selection page sets out the families by supply and duty class, which is the right entry point when the frame size has not been fixed, and the news and technical index collects the technical notes that sit behind this series.

What is missing, and how would it be closed?

One document would close it: the manufacturer's page for the air-conditioning rotary range that prints C-R224H3R with its displacement, capacity, input and coefficient of performance at a stated test condition. The 2024 catalogue does not carry that row. It carries the code rule, five legacy rows at about twice the block divided by ten, one legacy row at exactly the block divided by ten, and an air-conditioning row for the 223 class under a different designation.

Two routes would close the gap without waiting for a document. A nameplate photograph gives the refrigerant, the supply, the stamped displacement where the manufacturer prints one, and the serial, which identifies the build. A measured comparison against a known-good unit of the same class gives the capacity by substitution, which is how a service shop would settle it in practice.

Until one of those arrives, this article is a specification guide rather than a data sheet, and it is written to be read that way.

How was this article checked?

Three document families were read against each other: the manufacturer's 2024 rotary catalogue, a parts catalogue entry that names this model with its supply and refrigerant, and three retail listings. The catalogue was read page by page because the model code rule is printed on a page that has nothing else in common with the specification tables, and the row set that contradicts a literal reading of the block is spread across three different pages.

No capacity, input power or coefficient of performance is stated for C-R224H3R anywhere in this article, because no source prints one. Where neighbouring rows appear, they carry their own model numbers and their own duty bands, and the text says so at each occurrence.

Two arithmetic checks were run and both are visible above: the ratio column in the displacement table, and the coefficient of performance of the 223 class row, which closes as 10,100 divided by 3,570 to 2.83.

Frequently asked questions

Is the 224 block a displacement of 22.4 cm3/rev?

Not reliably. One of the two printed rules reads the block as a displacement times ten, which would give 22.4; the other reads the same three digits as a motor output power. Five legacy rows in the same catalogue print about twice the block divided by ten, and one prints exactly that figure. The block identifies a class; the row identifies the displacement.

Is it an R22 compressor?

The parts catalogue that names the model says R22, and two retail listings agree on the surrounding details. The digit after the use letter would mean R32 under the printed legend. Treat R22 as the working reading and confirm it from the nameplate.

What is the cooling capacity?

No source prints one for this designation, so none is quoted. The nearest published row of the same class, C-RN223H3C, prints 10,100 W at 3,570 W input, but that is a different designation for a different duty and is not this model's rating.

Is 3 HP a real rating?

Three HP is what two retail listings call it, and it is a class label rather than a printed rating row. The catalogue's power column for this frame class sits around 3.5 kW of input, which is not the same thing as 3 HP of motor output. Ask for the printed rating before designing to either number.

Can it be used on a 50 Hz and a 60 Hz supply?

The documented build is 200-220 V three phase at 50 Hz. A rotary running at 60 Hz turns twenty percent faster, so capacity and current both move even where the voltage matches. Confirm the frequency of the intended equipment before assuming a dual-frequency build.

What do the R, U and S tails mean?

They separate customer builds on the same compressor. A parts catalogue lists C-R224H3R against one equipment maker and C-R224H3U against another, with the same supply and the same refrigerant. Treat them as different spares.

Can it be used for freezing duty?

No. The H in the string places it in the high-back-pressure, air-conditioning band. Freezing duty needs a low-back-pressure machine, the catalogue prints what that family looks like, and the freezer variant page in the supplier's range shows the build in practice.

Where can comparable Sanyo rotary models be seen?

The supplier's Sanyo rotary range lists the models currently carried, and the class 22 pages in that range print the displacement and capacity that the catalogue rows carry. Comparing a refrigeration row with an air-conditioning row of the same class shows why duty band has to be settled before any number is used.

Sources