Specifications

Page 20 of 36 / IM 1049-4
Start-up
Units must be checked for water leaks upon initial water system
start-up. Water leaks may be a result of mishandling or damage
during shipping. Failure by the installing contractor to check for
leaks upon start-up of the water system could result in property
damage.
CAUTION
1. Open all valves to full open position and turn on power to
the unit.
2. Setthethermostatfor"FanOnly"operationbyselecting
"Off" at the system switch and "On" at the fan switch. If
"Auto" fan operation is selected, the fan will cycle with
the compressor.
3. Forthoseunitsthathavetwo-speedmotors,reconnectfor
low speed operation if necessary.
4. Setthermostatto“Cool.”Ifthethermostatisanautomatic
changeover type, simply set the cooling temperature to
the lowest temperature. On manual changeover types,
additionallyselect“Cool”atthesystemswitch.
Again, many units have time delays help protect the
compressor(s) against short cycling.
 Afterafewminutesofoperation,checkthedischarge
grilles for cool air delivery. Measure the temperature
differencebetweenenteringandleavingwater.Itshould
beapproximately1-1⁄2timesgreaterthantheheating
mode temperature difference. For example, if the
cooling temperature difference is 15°F (8°C), the heating
temperaturedifferenceshouldbe10°F(5°C).
 Withoutautomaticowcontrolvalves,targetacooling
temperature difference of 10°F to 14°F (5°C to 8°C).
Adjustthecombinationshutoff/balancingvalveinthe
returnlinetoawaterowratewhichwillresultinthe
10˚Fto14°F(5°Cto8°C)difference.
5. Setthermostatto“Heat.”Ifthethermostatistheautomatic
changeovertype,setsystemswitchtothe“Auto”position
and depress the heat setting to the highest temperature.
Someunitshavebuilt-intimedelayswhichprevent
the compressor from immediately starting. With most
control schemes, the fan will start immediately. After a
fewminutesofcompressoroperation,checkforwarm
airdeliveryatdischargegrille.Ifthisisa“coldbuilding”
start-up,leaveunitrunninguntilreturnairtotheunitisat
least 65°F (18°C).
Unit Size 042 through 060 (265-60-1), (208/230-1) &
(208/230-3)
Fanmotorsonunitsizes042-060involtages265-60-1,
208/230-1and208/230-3(Figure 26)allhaveave-position
terminalblock.Inordertochangebetweenhighandlow
speed,interchangethewiresontheblackandredterminals.
Figure 26: Sizes 042 through 070 (265-60-1), (208/230-1),
(208/230-3)
Unit Size 024 through 036 (208/230-3)
Fanmotorsonunitsizes024-036involtages208/230-3
(Figure 27)allhaveafour-positionterminalblock.Inorderto
changebetweenhighandlowspeed,interchangethewireson
theblackandredterminals.
Figure 27: Sizes 024 through 036 (208/230-3)
Notes: All motors have a wiring label that is keyed for proper
wiringoperation.Checkunitwiringdiagram(on
electricalaccesspanel)forproperunitoperation.Not
all labels are the same.
Units leaving the factory are wired for high or low
fanspeed(seeTable5onpage19 for fan speed
settings).
 Labelislocatedonthebackoftheterminalblock.
(Optional) ECM Motor
TheECMmotorwillmaintaintheratedairowasstaticpres-
sureincreasesordecreaseswithintheunit’soperatingrange.
Contactthefactoryat315-253-2771or800-432-1342ifan
alternateairowsettingisrequired.