Envision R-410A - Closed Loop Ground Source Systems

9
ENVISION RESIDENTIAL INSTALLATION MANUAL
Figure 7: Closed Loop Ground Source Application
Closed Loop Ground Source Systems
Note: Forclosedloopsystemswithantifreezeprotection,setSW2-2tothe“loop”position(seetableonpage28).
Oncepipingiscompletedbetweentheunit,pumpsandthegroundloop(seegurebelow),nalpurgingandcharging
oftheloopisrequired.Aushcart(ora1.5HPpumpminimum)isneededtoachieveadequateowvelocityintheloopto
purge air and dirt particles from the loop itself. Antifreeze solution is used in most areas to prevent freezing. Flush the sys-
temadequatelytoremoveasmuchairaspossiblethenpressurizethelooptoastaticpressureof40-50PSI(summer)or
50-75PSI(winter).Thisisnormallyadequateforgoodsystemoperation.Loopstaticpressurewilluctuatewiththe
seasons.Pressureswillbehigherinthewintermonthsthanduringthecoolingseason.Thisuctuationisnormalandshould
be considered when initially charging the system.
Afterpressurization,besuretoopentheplug1turnintheendofthelooppumpmotor(s)(ifapplicable)toallowtrapped
airtobedischargedandtoensurethatthemotorhousinghasbeenooded.Ensurethatthelooppumpsprovideadequate
owthroughtheunit(s)bycheckingthepressuredropacrosstheheatexchangerandcomparingittotheunitcapacitydata
inthespecicationcatalog.2.5to3GPMofowpertonofcoolingcapacityisrecommendedinearthloopapplications.
Multiple Units on
One Flow Center
When two units are connected to
one loop pumping system, pump control is
automatically achieved by connecting the
SLterminalsonconnectorP2inbothunits
with2-wirethermostatwire.Theseterminals
arepolaritydependant(seeFigure8).The
loop pump(s) may be powered from either
unit, whichever is more convenient. If either
unit calls, the loop pump(s) will automati-
callystart.Theuseoftwounitsononeow
centerisgenerallylimitedtoatotalof20
GPMcapacity.
Envision to
Electromechanical Units
Shut
Down
CC
SL1
In
SL1
Out
Envision Unit #1
To Electromechanical Unit
C
S
Shut
Down
CC
Shut
Down
CC
SL1
In
SL1
Out
SL1
In
SL1
Out
Single Speed
Envision Unit #1
With pump
wired to Unit 1
With pump
wired to
Unit 2
Envision to Envision
Microprocessor Units
Envision Unit #2
Single Speed
With pump
wired to Unit 1
With pump
wired to
Unit 2
Shut
Down
CC
Shut
Down
CC
SL1
In
SL1
Out
SL1
In
SL1
Out
Dual Capacity
Envision Unit #1
Envision Unit #2
Dual Capacity
Envision to Envision
Microprocessor Units
Figure 8: Primary/Secondary Hook-up
Flexible Duct
Collar
Vibration Absorbing Pad
P/T Plugs
Drain
Desuperheater
Connections
Auxiliary
Heater
Knockout
Low
Voltage to
Thermostat
Unit Supply
Auxiliary Heat
Supply
Insulated piping
or hose kit
Disconnects
(If Applicable)
Unit Power
P/T
TO
LOOP
GeoLink
®
Flow
Center
GeoLink
®
Polyethylene w/
Armaflex
®
Insulation
Note: Additional information can be found
inFlowCenterinstallationmanual(IM1961)
andFlushCartmanual(WFS302).