Krack MXA-06 User Manual
Microchannel
REMOTE AIR-COOLED CONDENSER
Technical Bulletin: MXCC_001_071015
Products that provide lasting solutions.
Microchannel Remote Air-Cooled Condenser
Krack’s new Microchannel Remote Air-Cooled Condenser incorporates
a new patented modular assembly.
n Smaller size and less weight reduces cost in the building construction.
n The new coil has less internal volume resulting in a significant reduction
in refrigerant charge. Less refrigerant is environmentally friendly.
n Coil slabs are easily replaced from the rear of the unit.
Environmentally Friendly Benefits
Krack, a Hussmann
Corporation brand,
has a long tradition
of leadership and
product innovation
in the refrigeration
n Reduced Coil Internal Volume - Resulting in a significant reduction
in condenser operating and flooding charge.
n Quiet Fans - “Swept-wing” blade design offers lower noise levels at
the same speed. Quiet multi-bladed direct driven propeller fans provide
uniform air distribution through the coil. Venturi fan orifices optimize
efficiency. Lower noise condensers can translate into savings by
minimizing the need for costly noise barriers.
n California Energy Commission - All Microchannel condensers are
compliant with CEC Title 24 condenser efficiency requirements.
industry.
Table of Contents
Benefit and Features 1
System Selections 2
Model Key 2
Applications 3
Performance Data 4
Dimensional Data
- Standard Model 5
- Receiver Model 6
Receiver Data 6
Control System 7
Electrical Motor AMP Data 7
Electrical Motor Watts Data 8
Control Panel Nomenclature 8
Condenser Control Panel 9
MICROCHANNEL REMOTE AIR-COOLED CONDENSER
Specifications subject to change without notice.
Microchannel Remote Air-Cooled Condenser
US
Benefits and Features
REMOTE AIR-COOLED CONDENSER
Patented Microchannel Condenser Modular
Assembly Design (Patent #6988538)
n Arranged for vertical air discharge.
n Multi-fan sections compartmented to allow
individual fan cycling while preventing off-fan
“windmilling.”
n Removable end panel for clean out and service
access.
Corrosion Resistant
n All models employ mill galvanized steel fan
sections and coil side baffles.
n Legs are heavy mill gauge galvanized steel.
n Corrosion resistance is improved with an all aluminum
microchannel coil, reducing the chance for galvanic
corrosion that exists on traditional copper tube and
aluminum fin coils. Additionally, the microchannel
tubes are coated with a sacrificial metallic layer that
is less noble than the tube, fin, and braze material.
PROTECTIVE COVER PANELS
Weather Resistant Fan Motors
n Outdoor condenser motors designed with ball
bearings inherent overheat protection in each phase;
shaft slingers; enclosure, hardware, and lubrication
for all weather conditions.
n Each motor lead is wired to terminals in an electrical
enclosure.
n Inverter duty suitable fan motors are standard.
COMPACT DESIGN
n Lighter weight.
- Up to 35% weight reduction compared to
traditional condenser design.
n Modular construction and fewer parts.
- Available in 2 to 14 fan models.
OPTIONAL FEATURES
n Electro-Fin coated coils.
n Mounted receiver.
n Reusable air filter.
n Winter reduction control solenoids.
n Modular isolation ball valves.
Modular Winter Reduction Solenoid
n Maintains condenser pressure by isolating coil sections
in conjunction with fan cycling.
n Reduction in coil volume results in reduced refrigerant
operating and flooding charge.
Versatile Fan Cycling Control Methods
n Electronic relay boards.
n Pressure fan cycling.
n Temperature fan cycling.
Replaceable High Efficiency Coil
n Extruded aluminum microchannel coil construction
increases coil efficiency, while reducing refrigerant
operating charge, unit weight and footprint.
n Unit design allows for coil replacement from rear
of unit.
MICROCHANNEL REMOTE AIR-COOLED CONDENSER
1
Specifications subject to change without notice.
Microchannel Remote Air-Cooled Condenser
EVAPORATOR
TEMP (˚F)
-40
-30
-20
-10
0
5
10
15
20
25
30
40
50
90
1.66
1.57
1.49
1.42
1.36
1.33
1.31
1.28
1.26
1.24
1.22
1.18
1.14
100
1.73
1.62
1.53
1.46
1.40
1.37
1.34
1.32
1.29
1.27
1.25
1.21
1.17
110
1.80
1.68
1.58
1.50
1.44
1.41
1.38
1.35
1.33
1.31
1.28
1.24
1.20
120
2.00
1.80
1.65
1.57
1.50
1.46
1.43
1.40
1.37
1.35
1.32
1.27
1.23
130
*
*
*
1.64
1.56
1.52
1.49
1.46
1.43
1.40
1.37
1.31
1.26
140
*
*
*
*
1.62
1.59
1.55
1.52
1.49
1.45
1.42
1.35
1.29
CONDENSING TEMPERATURE (˚F)
HERMETIC COMPRESSOR
EVAPORATOR
TEMP (˚F)
-30
-20
-10
0
10
20
30
40
50
90
1.37
1.33
1.28
1.24
1.21
1.17
1.14
1.12
1.09
100
1.42
1.37
1.32
1.28
1.24
1.20
1.17
1.15
1.12
110
1.47
1.42
1.37
1.32
1.28
1.24
1.20
1.17
1.14
120
*
1.47
1.42
1.37
1.32
1.28
1.24
1.20
1.17
130
*
*
1.47
1.41
1.36
1.32
1.27
1.23
1.20
140
*
*
*
1.47
1.42
1.37
1.32
1.28
1.24
CONDENSING TEMPERATURE (˚F)
OPEN COMPRESSOR
TABLE 1
TABLE 2
* Beyond the normal limits for single-stage compressor application.
* Beyond the normal limits for single-stage compressor application.
EVAPORATOR
TEMP (˚F)
-40
-30
-20
-10
0
5
10
15
20
25
30
40
50
90
1.66
1.57
1.49
1.42
1.36
1.33
1.31
1.28
1.26
1.24
1.22
1.18
1.14
100
1.73
1.62
1.53
1.46
1.40
1.37
1.34
1.32
1.29
1.27
1.25
1.21
1.17
110
1.80
1.68
1.58
1.50
1.44
1.41
1.38
1.35
1.33
1.31
1.28
1.24
1.20
120
2.00
1.80
1.65
1.57
1.50
1.46
1.43
1.40
1.37
1.35
1.32
1.27
1.23
130
*
*
*
1.64
1.56
1.52
1.49
1.46
1.43
1.40
1.37
1.31
1.26
140
*
*
*
*
1.62
1.59
1.55
1.52
1.49
1.45
1.42
1.35
1.29
CONDENSING TEMPERATURE (˚F)
HERMETIC COMPRESS
OR
TABLE 1
* Beyond the normal limits for single-stage compressor application.
System Selections
THR - Total Heat of Rejection
n Condenser total heat of rejection (BTU/h) is the sum of the
evaporator refrigeration effect and the heat of compression
which varies with compressor type and operating conditions.
THR Calculation Method
n THR = Open Reciprocating Compressor Capacity
(BTU/h) + (2545 x BHP)
n THR = Suction Gas Cooled Hermetic Reciprocating
Compressor Capacity (BTU/h) + (3413 x kW)
THR Estimated Method
n THR may be estimated by multiplying the rated
compressor BTU/h capacity by the compressor operating
condition factor shown in Table 1 or 2.
Multiply result by altitude factor when applicable.
EVAPORATOR
TEMP (˚F)
-30
-20
-10
10
20
30
40
50
* Beyond the normal limits for single-stage compressor application.
Model Key
UNIT TYPE:
MX = Microchannel
FAN/MOTOR
COMBINATION:
A=1 HP 850 RPM 30"
C=1-1/2 HP 850 RPM 30"
E=1/2 HP 575 RPM 30"
F=1-1/2 HP 1140 RPM 30"
0
CONDENSING TEMPERATURE (˚F)
90
1.37
1.33
1.28
1.24
1.21
1.17
1.14
1.12
1.09
MX F-06 M
TABLE 2
OPEN COMPRESSOR
100
1.42
1.37
1.32
1.28
1.24
1.20
1.17
1.15
1.12
110
120
1.47
1.42
1.47
1.37
1.42
1.32
1.37
1.28
1.32
1.24
1.28
1.20
1.24
1.17
1.20
1.14
1.17
130
*
TOTAL NUMBER OF FANS:
02 10
04 12
06 14
08
140
*
*
*
*
1.47
1.41
1.36
1.32
1.27
1.23
1.20
*
1.47
1.42
1.37
1.32
1.28
1.24
MOTOR VOLTAGE:
K= 208-230/3/60
M= 460/3/60
P= 575/3/60
U= 380/3/50 (Capacity Derate of Around 10%)
TABLE 1
HERMETIC COMPRESSO
EVAPORATOR
TEMP (˚F)
-40
-30
-20
-10
0
5
10
15
20
25
30
40
50
* Beyond the normal limits for single-stage compressor application.
CONDENSING TEMPERATURE (˚F)
90
100
110
1.66
1.73
1.80
1.57
1.62
1.68
1.49
1.53
1.58
1.42
1.46
1.50
1.36
1.40
1.44
1.33
1.37
1.41
1.31
1.34
1.38
1.28
1.32
1.35
1.26
1.29
1.33
1.24
1.27
1.31
1.22
1.25
1.28
1.18
1.21
1.24
1.14
1.17
1.20
TABLE 3
ALTITUDE
FEET
1,000
2,000
3,000
4,000
FACTOR
1.02
1.05
1.07
1.10
FEET
5,000
6,000
7,000
8,000
120
2.00
1.80
1.65
1.57
1.50
1.46
1.43
1.40
1.37
1.35
1.32
1.27
1.23
R
130
*
*
*
1.64
1.56
1.52
1.49
1.46
1.43
1.40
1.37
1.31
1.26
FACTOR
1.12
1.15
1.17
1.24
140
*
*
*
*
1.62
1.59
1.55
1.52
1.49
1.45
1.42
1.35
1.29
MICROCHANNEL REMOTE AIR-COOLED CONDENSER
2
Specifications subject to change without notice.
Microchannel Remote Air-Cooled Condenser
Applications
n Locate Condensers no closer than their width from walls
or other condensers. Avoid locations near exhaust fans,
plumbing vents, flues or chimneys.
n Parallel Condensers should be the same model resulting
in the same refrigerant side pressure drops. Compressor
discharge lines should have equal pressure drops to each
condenser.
n Condenser Refrigerant Charge for Summer conditions
are listed on the Performance Data Table. The additional
Winter Flooding charge required is difficult to predict
with fan cycling and is maximized with holdback; however,
the maximum additional refrigerant charge is also listed
on the Performance Data Table for Winter conditions
at -20˚F. The Summer operating and Winter maximum
flooding charge is substantially less than that required for
traditional tube and fin condensers due to the reduced
internal volume of the microchannel coils. Further
reduction in flooding charge can be obtained with the
“Modular Winter Reduction” option, by “shutting down”
the associated refrigerant circuit in combination with
fan cycling.
REFRIGERANT LINE CAPACITY DATA
n Receiver Capacity should be sized to store condenser
summer charge, plus the condenser low ambient
allowance, plus the evaporator charge, plus an allowance
for piping and heat reclaim coil charges.
n Compressor Discharge lines should be sized to minimize
pressure drops and maintain oil return gas velocities. Each
connection should be looped to the top of the condenser.
n Gravity Liquid Drain Lines should drop from each outlet as
low as possible before headering or running horizontally.
Pitch downhill to receiver.
n Off-Line Coil Sections will have refrigerant pressures
corresponding to the ambient. Check valves or isolating
valves should be installed in the liquid line drains to
prevent refrigerant migration and receiver pressure loss.
COPPER
LINE
SIZE
O.D.
5/8
7/8
1-1/8
1-3/8
1-5/8
2-1/8
2-5/8
LINE CAPACITY IN TONS
CONDENSER TO RECEIVERCOMPRESSOR
DISCHARGE LINE
R-404A R-407A R-134a
0.5 1.0 0.5 3.0 3.6 3.7 11.0 13.0 13.0
2.0 3.0 2.0 6.0 7.4 7.7 22.0 25.0 26.0
4.5 6.5 4.5 10.4 12.7 13.0 36.0 42.0 43.0
7.0 15.0 7.0 16.0 19.2 20.0 55.0 64.0 65.0
15.0 20.0 11.0 23.0 29.0 28.5 78.0 90.0 92.0
30.0 45.0 28.0 40.0 47.0 46.0 138.0 160.0 163.0
45.0 75.0 43.0 62.0 73.0 72.0 212.0 245.0 250.0
Capacity is compressor suction tons for application between -40ºF and +40ºF suction at condensing temperatures between 80ºF and 120ºF sat.
For multiple or unloading compressor application, the vertical discharge riser from the compressor may need to be one size smaller.
This table data is only to be used as a guide. For exact values, please calculate to your specific job line lengths and design pressure/temp values
LIQUID LINE 100’
R-404A R-407A R-134a
LBS. OF REFRIGERANT
LIQUID PER 100’
OF LENGTH
R-404A R-407A R-134a
using ASHRAE handbook or ARI refrigerant tables.
MICROCHANNEL REMOTE AIR-COOLED CONDENSER
Specifications subject to change without notice.
3
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