Greenheck Fan HEAT RECOVERY UNIT WITH EVAPORATIVE COOLING HRE-20 - Manual (Page 12)

12
Evaporative
Timer
Evaporative
Freeze
Protection
t2 settings
t1 settings
Temperature
Setting
AUTO DRAIN AND FILL WITH FREEZE PROTECTION
This system will automatically drain the sump tank and fill it with
fresh water at the field adjustable intervals, typically once every 24
hours . This flushes mineral build-up and debris from the tank to
promote low maintenance and increase media pad life . In addition,
the system will protect the evaporative cooler from freezing
by draining the sump tank and supply line when the outside
temperatures fall below the set point of the outside air sensor .
Typically, this is set at 45º to 50º F . The auto drain and fill outdoor
air sensor should be installed in an area that is shaded from direct
sunlight so the outside air sensor probe will detect an accurate air
temperature. Set the timer. Timer settings are t1:1.0, 10 min and
t2:0.4, 60h
PLUMBING FOR AUTO DRAIN AND FILL
1 . Run water supply line to the unit and install Water Supply Solenoid Valve (A) in this line as close to the
water source as possible .
2 . Install Drain Solenoid Valve (B) in the supply line as indicated below . From the outlet on the drain valve,
run line to a suitable drain location .
3 . Run an unobstructed drain line from the sump overflow to the drain trap as shown below .
4 . Install Sump Drain Solenoid Valve (C) in the drain line from the sump as indicated below . From the outlet
on this drain valve, run a line to a suitable drain location .
Note: Water Supply Solenoid Valve (A) is not the same as the Drain Solenoid valves (B) and (C) . Make sure to
use the proper valve for each location . Check your local code requirements for proper installation of this
type of system . Additional drain and supply plumbing may be needed to meet your local code .
Caution: All solenoid valves A, B, and C must be installed below the roof to protect the supply water line from
freezing . If these valves cannot be installed below the roof, an alternate method must be used to protect these
lines from freezing .
WATER CONTROL OPTIONS FOR EVAPORATIVE COOLING
Trap & Supply Line Configuration
with Auto Drain and Fill
A1
B1
15
NC
JC
COM
TIMER
JC
18
A2
16
VC
VB
VA
JOHNSON CONTROLLER
24VAC COM SENSOR
24V AC POWER AND WIRING
BY OTHERS
SENSOR
OUTDOOR AIR
VALVE "A"
VALVE "B"
VALVE "C"
TIMER
OUTDOOR AIR SENSOR
T1
AUTO DRAIN AND FILL WITH FREEZE PROTECTION
PART DESCRIPTIONS
VALVE, WATER SUPPLY (A)
VALVE, DRAIN (B)
VALVE, SUMP DRAIN (C)
24 HOUR TIMER
JOHNSON CONTROLLER
GREENHECK P/N QTY.
07458032 1
07381940 1
05461262 1
05461263 1
05461264 1
OUTDOOR AIR SENSOR 07458298 1
1/2 PIPE SIZE (NC)
1/4 PIPE SIZE (NO)
3/4 PIPE SIZE (NO)
-
25
25
25
-
-
HOLDING VA INRUSH VA
-
70
50
70
-
-
SUMP
EVAPORATIVE
COOLING MEDIA
ROOF CURB
ROOF LINE
TRAP
DRAIN LINE
SUPPLY LINE
WATER SUPPLY SOLENOID VALVE (A)–NORMALLY CLOSED
1/2 INCH PIPE SIZE
DRAIN SOLENOID VALVE (B)–NORMALLY OPEN
1/4 INCH PIPE SIZE
SUMP DRAIN SOLENOID VALVE (C)–NORMALLY OPEN
3/4 INCH PIPE SIZE
SIDE OF HRE UNIT
SUMP DRAIN PIPE
(TO EACH EVAP)
SUMP OVERFLOW PIPE
(TO EACH EVAP)
THE SYSTEM WILL AUTOMATICALLY DRAIN THE SUMP TANK AND FILL IT WITH FRESH WATER AT THE FIELD ADJUSTABLE INTERVALS, TYPICAL SETTINGS ARE t1 = 24HRS
t2 = 10 MIN. WITH THE DIP SWITCH IN THE DOWN POSITION. THIS FLUSHES MINERAL BUILD-UP AND DEBRIS FROM THE TANK TO PROMOTE LOW MAINTENANCE AND
INCREASE MEDIA PAD LIFE. IN ADDITION, THE SYSTEM WILL PROTECT THE EVAPORATIVE COOLER FROM FREEZING BY DRAINING THE SUMP TANK AND SUPPLY LINE
WHEN THE OUTSIDE TEMPERATURES FALL BELOW THE SET POINT OF THE OUTDOOR AIR SENSOR. TYPICALLY, THIS IS SET AT 45° TO 50° F. THE AUTO DRAIN AND FILL
OUTDOOR AIR SENSOR SHOULD BE INSTALLED IN AN AREA THAT IS SHADED FROM DIRECT SUNLIGHT SO THE SENSOR PROBE WILL DETECT AN ACCURATE AIR
TEMPERATURE.
THE FOLLOWING COMPONENTS SHIP FROM GREENHECK WITH HRE (INSTALLATION, WIRING, AND POWER BY OTHERS)
WATER LINE CONNECTION
AT FLOAT IS 1/4 INCH