Hussmann KRACK MK Series, Installation And Operation Manual

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MK/MV – Medium Profile Series Unit Coolers (E206993_M) 17
Table 7 MV LOW TEMPERATURE/HIGH VELOCITY - ELECTRIC DEFROST
MODEL
CFM
STANDARD
CIRCUITS
NOZZLE
R404A
NOZZLE
R407A
NOZZLE
R448A
MV14E-73 4790 5 L-1 L-1 L-1-1/2
MV14E-100 4300 6 L-1-1/2 L-1-1/2 L-2
MV14E-128 4130 8 L-2 L-2 L-2-1/2
MV24E-146 9580 10 J-2-1/2 J-2 J-2-1/2
MV24E-200 8600 10 J-3 J-2-1/2 J-3
MV24E-256 8260 13 J-4 J-3 J-4
MV34E-300 12900 15 G-5 G-4 G-5
MV34E-383 12390 20 G-8 G-5 G-6
MV44E-512 16520 20 G-12 G-6 G-8
MV16E-93 4405 5 L-1-1/2 L-1-1/2 L-2
MV16E-126 3955 6 L-2 L-1-1/2 L-2
MV16E-155 3800 8 L-2-1/2 L-2 L-2-1/2
MV26E-186 8810 10 J-3 J-2-1/2 J-3
MV26E-252 7910 10 J-5 J-3 J-4
MV26E-310 7600 13 J-6 J-4 J-5
MV36E-378 11865 15 G-8 G-5 G-6
MV36E-465 11400 20 G-10 G-6 G-8
MV46E-620 15200 20 G-12 G-10 G-12
*Consult factory.
Note: Low temperature distributor nozzle selections are based on -20
°
F suction temperature, 10
°
F T.D.
and 85
°
F liquid temperature.
4.6 EXPANSION VALVE
Before mounting the unit, install the expansion valve and connect the equalizer tube. The expansion
valve should be installed directly to the distributor body or as close as possible with no elbows or bends.
Locate the expansion valve bulb on a horizontal length of suction line as close to the suction header as
possible. Position the bulb in a 3, 4, 8, or 9 o’clock position (do not position on the bottom side of the
pipe). Clamp the bulb down flush and tightly against the pipe and insulate. Never locate the bulb in a
trap or downstream from a trap.
Expansion valves are adjusted at the factory prior to shipment. The setting will be correct for many
applications, but in other applications adjustments may be needed. It is important that the operation of
the expansion valve be checked after the system has balanced out at the desired room temperature. If
the coil is being starved, it is necessary to reduce the superheat setting of the valve by turning the
adjusting stem counterclockwise. If the superheat is too low, it is necessary to increase the superheat
setting of the valve by turning the adjusting stem clockwise. It is recommended that for a 10
°
F to 12
°
F
T.D. system, the valve should be adjusted to maintain 5
°
F to 6
°
F superheat.