Publication date: copy write January 2017 written material by
Myles Opheim
DAIKIN Hydraulics
Word through the grapevine is that specific Daikin models are
factory supported for 6-8 years. The "6" and "7" series hydraulic
chillers broke this corporate rule-of-thumb because they were
development programs for the "8" series and use of R-410A. As of
this writing (2017) Daikin hydraulics is manufacturing the "9"
series.
1. A breakdown of Daikin's changes on the predominant models
follow:
The "series" designation was introduced into the North American
market in the 1980s with generation "3" and Daikin hydraulics has
progressed up through (examples) AKS-103 / AKS-104 / AKS-105 which
were all on-off-on constant speed compressor models using R-22.
Note: AKSJ, AKM, AKD and other model designations exist. The next
introduction among model changes arrived with the variable speed
compressor designs.
An example is AKZ-106 which was an invertor duty (variable
speed) AC compressor with R-22 refrigerant. AKZ-327 was an invertor
duty (variable speed) DC compressor design using R-407C.
2. kilowatt Cooling Capacity versus Compressor Motor Horsepower
model number designations:
The AKZ-328 family became their first variable speed DC
compressor using R-410A. The AKZ-327 was invertor duty AC but the
first designation of kw/hour cooling capacity in the model number.
The current (2017) model production (2017) became available in the
than the AKZ-329 with DC variable compressor and R-410A
available
approximate 2010/2011 time frame
Reference: JIS Z8601 two digit cooling capacity (2 digit x
10)
AKZ-148 (14 x 10 = 140 kilo watt/hour)
AKZ-328 (32 x 10 = 320 kilo watt/hour)
AKZ-438 (48 x 10 = 480 kilo watt/hour)
AKZ-568 (56 x 10 = 560 kilo watt/hour)
AKZ-908 (90 x 10 = 900 kilo watt/hour)
3. Compressor Motor Horsepower Model Numbers (.33, .54, 1.0,
2.0, 3.0)
Chillers Described By Series "1,2,3,4,5,"
3a. PAST: AK~~3 is no longer built or factory supported as of
this entry (2017). The series utilized R-22, had constant speed one
(1) phase hermetic compressors, a capillary tube expansion device,
and a three (3) phase circulating pump motor. If the condenser fan
motor was separate from the circulating pump motor, then this fan
motor was also single (1) phase. This series is one of the easiest
to maintain from off-the-shelf, aftermarket parts.
3a. Design Flaw: "Close coupled" keyway shafting connection on
circulating motor and pump. This made things OEM.
3b. PAST: AK~~4 is no longer built or factory supported (2017).
Because it is so similar to the series "5" one can almost
exclusively substitute "5" parts unless circuit board components
vary. The "4" series utilized R-22, had a constant speed three (3)
phase hermetic compressor, a capillary tube expansion device, and a
three (3) phase circulating pump motor. Some of the replacement
parts were obtained through aftermarket contacts.
3b. Design Flaw: "Close-coupled" keyway shafting on circulating
motor and pump for closed loop applications.
3c. PAST: AK~~5 is no longer factory built or supported (2017).
The North American representative's claim was that the factory
would do so until 2012.
The "5" series utilized R-22, had a constant speed three (3)
phase hermetic compressor, a capillary tube expansion device, and a
three (3) phase circulating pump motor on the "closed loop"
models.
3c. Design Push: "Close-coupled" keyway shafting on circulating
motor and pump were changed out to "common shaft" designs relative
to the pump and motor. That means replacement with a complete
assembly. This author is unaware of any "5" series models that
may have the condenser fan motor separate from the circulating pump
motor.
4. kilowatt cooling capacity Model Numbers ("6,7,8,9"
designations)
Chillers Described By Series "7,8,9"
CURRENT: AK~~6 replaced the "5" series in a marketing strategy
of Daikin Hydraulics.
The author does not believe that this series is being
manufactured but factory support is available. The "6" series
utilized R-407c which is a retrofit gas for R-22. A constant speed
three (3) phase hermetic compressor, capillary tube expansion
device, and a three (3) phase circulating pump motor on the "closed
loop" models. Many of the parts can be obtained through aftermarket
contacts. This author is unaware of models that may have the
condenser fan motor separate from the circulating
pump motor. CURRENT: AK~~7 is replacing the "6" series in a
marketing strategy of Daikin's. The author does not have good
first-hand knowledge of this series. Factory support is available.
The "7" series is believed to have utilized R-407c which is a
retrofit refrigerant for R-22. CURRENT: AKS_8 is a
radical departure in marketing strategy on the part of Daikin.
The "8" series utilizes R-410a refrigerant which is ozone friendly,
and the refrigerant is a high pressure application compared to
R-22, R-407c, and R-134a. Variable speed, direct current hermetic
compressor design provides for a "throttling
effect". The expansion device is electronically controlled to
enhance this " throttling ", and all control circuitry voltages are
direct current. It is not known by this author what type of current
the circulating pump motor uses on the "closed loop" models, nor is
he aware of the models that may have the
condenser fan motor separate from the circulating pump motor.
Series "8" chillers are a radical departure from low cost
manufacturers who remain with constant speed / on-off operation of
their product. This series will keep most customers coming back to
Daikin for replacement parts as the unit ages.
Daikin customers have some nice options available in replacement
of the Daikin brand.
For example:
Any brand with a constant speed on-off-on compressor operation
can be utilized in your machine tool application as long as you
include a reservoir (tank). This requirement is no different than
air
conditioning your home or any other building. Heat gain is
"matched" relative to the reservoir by starting and stopping the
compressor to pre-determined temperature bands.
In machine shop applications a 3-phase compressor allows for
unlimited start-stop cycles in a 1 hour period so compressor life
isn't compromised.
Observations:
1. Daikin Frameless Construction, bulkhead mounting photographs
1 and 2. 2. Kanto Seiki framed component mounting photograph 3. 3.
Habor Precise framed component mounting photograph 4.