Crown Bermuda Installation Manual

Feeder Wiring for Boilers Equipped with McDonnell & Miller #67 Low Water Cut-offs

Figures14aand14bshowfeederwiringforMcDonnell&Miller#101A,McDonnell&MillerWF2-U-24andHydrolevel

VXT-24feedersonboilersequippedwith#67lowwatercutoffs.Thefollowingpointsapplytoallfeederwiringto#67low

watercut-offs:

• Useaseparatetransformertopowerthefeeder.Donotusethetransformerontheboiler.

• Itisnotnecessarytotouchanyofthe24voltfactoryboilerwiringwhenconnectingafeedertoa#67equipped

boiler.

• Do NOTinstallajumperbetweenterminals2and3onthe#67lowwatercutoff.

Indirect Water Heater Wiring

Figure15showseldwiringforanindirectwaterheater.AHoneywellR845AorequivalentDPSTrelayandtransformer

isrequired.ThehighlimitdescribedinPartIXmustalsobesuppliedbytheinstaller.Acallforheatfromtheindirectwater

heaterthermostatwillenergizetherelaymakingbothsetsofcontacts.Onesetofthesecontactsthenenergizesthecirculator.

Theothersetofcontactswillmakethe“T”and“T”contactsontheburnerprimarycontrol,ringtheburner.Iftheboiler

watertemperatureexceedsthehighlimitsettingof180F,thehighlimitwillopenthe“T”-“T”circuitandtheburnerwill

shutdown.

Ifthereisacallforspaceheat,theheatingthermostatwillmakethe“T”-”T”circuitandtheboilerwillrewithoutregard

tothestatusoftheindirectwaterheater.Thelowwatercut-offandpressurelimitcontrolwillinterrupt120voltpowertothe

burnerintheeventofalowwaterorexcessivepressurecondition.

FIGURE14a:WIRINGMCDONNELL&MILLER101AORTWO-WIRE H Y D R O L E V E L  V X T- 2 4  F E E D E R 

 TOBOILEREQUIPPEDWITH#67L.W.C.O.

CAUTION

DO NOT INSTALL

JUMPERBETWEEN2&3

ON #67 L.W.C.O.