24 • Refrigeration
REFRIgERATION
HOT GAS DEFROST - SETTINGS
for defrost settings.
The timer starts the hot gas defrost cycle by energizing a solenoid, reversing valve, or directional valve. The hot gas is injected from the source
into the suction line of the evaporator to be defrosted. The hot gas flows into the serpentine coil attached to the floor of the case and then into
the evaporator. Condensed liquid leaves the evaporator through the side port distributor, through a check valve into the liquid line.
Hot gas defrost termination temperature is set at 65°F. At ASHRAE test conditions, the observed durations are typically 12-22 minutes. Hot gas
defrost termination sensors are located on the TXV bypass line ("dump line").
HOT GAS DEFROST - COMPONENTS
for defrost components.
Freezers equipped for hot gas defrost include a side port distributor, a TXV check valve for coil defrost, and a suction line check valve to bypass
hot gas to the serpentine coil. The serpentine coil is attached to the bottom of the pan to ensure pan and drain defrost.
FIGURE 39: Heater Wires for 3-Phase Defrost
8
10
9
11
7
13
6
5
12
4
3
2
1
14
30" HOT GAS DEFROST
DWG NO.SP-3000 REV. E
I/O MANUAL
TOLERANCES:
(PER SP-0457)
STANDARD
RELEASED
PART WEIGHT:
(IN LBS)
CAD DRAWING
NO MANUAL REVISIONS
COPYRIGHT INFORMATION
THIS DRAWING AND THE INFORMATION CONTAINED WITHIN, IS
THE SOLE PROPERTY OF ZERO ZONE, INC. ANY USE OF THIS
DOCUMENT OR DISCLOSURE OF ITS CONTENTS; BY
REPRODUCTION OR OTHER MEANS, WITHOUT THE WRITTEN
CONSENT OF ZERO ZONE, INC. IS STRICTLY PROHIBITED.
(NONE)
(NONE)
FINISH:
(PER SP-0154)
MATERIAL:
(PER SP-0404)
(UNLESS OTHERWISE SPECIFIED)
A
SHEET
SIZE
NOT TO SCALE
JHZ
SCALE:
MODELED BY:
DRAWN BY:
UNLESS OTHERWISE
SPECIFIED, ALL DIMENSIONS
ARE IN DECIMAL INCH
8/3/2012
E
1 OF 1
SP-3000
HOT GAS BYPASS VZ LAYOUT,
SHEET:
DATE:
REVISION
ZERO ZONE, INC.
110 NORTH OAKRIDGE DRIVE
NORTH PRAIRIE, WISCONSIN
USA 53153
DRAWING No:
DESCRIPTION:
BY
DATE
ECN No.
REVISION DESCRIPTION
No.
JHZ
11/26/2012
9651
REVISE BALLOON 14 DEFROST
E
REVISION INFORMATION
TERMINATION PROBE LOCATION
ITEM
PART
1
Coil Cover
2
Fan
3
Fan Housing
4
Coil
5
Check Valve
6
Serpentine
7
Heat Exchanger
8
TXV
9
Hand Valve (Optional)
10
Drier (Optional)
11
Check Valve
12
Hot Gas Solenoid Valve (Optional)
13
Hot Gas Clip
14
Defrost Termination Probe
FIGURE 40: Hot Gas Defrost Components
