Specifications

SPECIFICATIONS:
StandardListings&Approvals.......................................UL,CUL
WATERHEATERS•BOILERS•PARTS&ACCESSORIES
AERCOINTERNATIONAL,INC.
100ORITANIDR.•BLAUVELT,NY10913
(845)580-8000•FAX(845)580-8090
www.aerco.com
RepresentedBy:
Specicationssubjecttochangewithoutpriornotice.
ConsultwebsiteorcontactAERCO.
BST2/2014NY
NOTES:
• Setback Setpoint Gradual Decrease – Whenever
boilers are running at a high rate and the Setback-
Setpointfeatureisactivated,thesuddendecreasein
setpointwillcausethePIDtodrasticallycutbackon
rerate.This sudden decrease inreratewilloften
cause the boilers to drop below their Stop Levels
causing them to turn off, thereby causing excessive
cyclingandlossofheatingcapacitywhiletheboilers
can re-ignite. The Setback-Setpoint gradual
decrease featurewilldecreasethesetpoint,lowered
by the activation of the Setback-Setpoint feature, at
aslow rate thereby allowingthe PID to recoverand
preventanyboilersfromshuttingdownifnotrequired
todoso.
• Warm-Up and Low-Fire-Delay Fire Rate Hold –
Whenanextraboilerisignitedtomeetdemand,the
rerateofallignitedboilerswillbeheldattheirpresent
level until the newly ignited boiler has completed
Warm-upandLowFireDelay.Whenthenewlyignited
boiler has completed Warm-up and Low Fire Delay,
allboilerrerateswilldecreaseto approx 30% Fire
Rate.Allboilerrerateswillthenrisetogethertothe
requiredreratetomeetdemand.
• Next Turn On Valve Position – When all ignited
boilersreachorexceedtheBST Next on VPvalue,
anotherboilerwillbeignitedtosharetheload(ifone
isavailable).Thedefaultvalueis50%.Thisfeatureis
also useful if a user wishes to always have as few
boilersonatanyonetime.SettingtheBST Next on
VPvaluetoahighnumber(Example100%)willonly
igniteanewboilerifallcurrentlyignitedboilersreach
theirtotalBTUcapacity(100%).
• Warm-Up and Low-Fire-Delay PID Hold–
WheneveranyboilerisineitherWarm-uporLow
FireDelay,theIntegralportionoftheBSTPIDwill
befrozeninordertopreventthePIDfromwinding
uptoohighcausingthetemperaturetoovershoot
causinganover-tempcondition.
• Setpoint Approach Rate control–Toavoidheader
temperatureovershoots,whenevertheheader
temperaturenearsthesetpointtemperatureatarate
tooquicklytopreventatemperatureovershoot,the
BSTreratewilltemporarilydecreaseinorderto
lowerthetemperaturerisemomentum.Thisfeature
willhelpavoidtemperatureovershootsdueto
variableowaswellasotherconditions.