Honeywell L7224A,C Zone Request ZR terminal is connected to, Time is applied, see Table, Minute

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L7224A,C; L7248A,C,L OIL ELECTRONIC AQUASTAT® CONTROLLERS

Table 6. L7224/L7248 Controller Operating Sequence.

 

 

Action

System Response

Thermostat calls for heat.

Circulator starts when water temperature is above Low Limit setting (if

 

applicable) or above the Thermal Purge Temperature Limit (tPL) if

 

Thermal Purge is enabled. Boiler temperature is checked. Burner

 

starts when water temperature is below High Limit setting minus the

 

differential or at or below the Thermal Purge Temperature Limit (tPL)

 

for cold start boilers if the Thermal Purge Temperature Limit is

 

enabled. If tPL is enabled, the burner may also start if the boiler

 

temperature is cooling at 10 ºF or greater per minute or the Thermal

 

Purge Time Delay (tPt) has expired.

 

If Anti Short-Cycle Time is enabled, the burner does not start until the

 

set Anti Short-Cycle Time between cycles expires after the previous

 

call for heat was satisfied.

 

 

Boiler temperature exceeds the High Limit.

Burner is turned off. Burner restarts when the water temperature

 

drops below the High Limit setting minus the Differential. If Thermal

 

Purge is enabled, the burner is turned on when either the Thermal

 

Purge Temperature Limit is reached, the Thermal Purge Time Delay

 

has expired or the boiler temperature cooling rate exceeds 10 ºF/

 

minute.

 

 

Thermostat is satisfied.

Circulator and burner turn off.

 

 

Boiler temperature drops below the Low Limit

Burner is turned on, Circulator is turned off. Burner stops when the

setting minus the differential (if applicable).

water temperature exceeds the Low Limit setting. Power to Zc is

 

removed.

 

 

Error condition

If an error condition is detected, all outputs except ZC are shut down.

1-5.

Burner is off. Control continues to function and restarts when error is

 

corrected.

 

During the error check sequence, the system checks for drift in the

 

sensor and corrosion in the connections.

 

 

Error condition 6.

EnviraCOM communication is not available.

 

 

Error condition 7.

The control has reset the High Limit, Low Limit and Differential setting to

 

a default setting and will continue to run at those settings.

 

Performance of the system will be degraded.

 

 

Error condition 8.

If the error condition is detected, all outputs except ZC are shut down.

 

Burner is off. Control continues to function and restarts when all three

 

user keys have been pressed longer than 60 seconds.

 

 

Error condition 9*.

System continues to run with no outdoor reset functionality

 

 

Error condition 10*.

System continues to run with outdoor reset parameters enabled as

 

programmed. Error cleared automatically.

 

 

Error condition 11*.

System continues to run with boiler temp set to High Limit.

 

 

* Error condition only available when the Outdoor Reset Module is installed.

Table 7. L7224/L7248 Controller Operating Sequence with multiple zones connected through the ZR terminal.

Action

System Response

Zone Request (ZR) terminal is connected to

Boiler temperature is checked. Burner starts when water temperature

L1 (Zone calls for heat).

is below High Limit setting or at or below the Thermal Purge

 

Temperature Limit (tPL) for cold start boilers if the Thermal Purge

 

Temperature Limit is enabled. If tPL is enabled, the burner may also

 

start if the boiler temperature is cooling at 10 ºF or greater per minute

 

or the Thermal Purge Time Delay (tPt) has expired. Anti Short-Cycle

 

Time is applied, see Table 6.

 

 

Boiler temperature exceeds the High Limit.

Burner is turned off. Burner restarts when the water temperature

 

drops below the High Limit setting minus the Differential. If Thermal

 

Purge is enabled, the burner is turned on when either the Thermal

 

Purge Temperature Limit is reached, the Thermal Purge Time Delay

 

has expired or the boiler temperature cooling rate exceeds 10 ºF/

 

minute.

 

 

Zone Request input is de-energized (Zones

Burner turns off.

are satisfied).

 

 

 

Boiler temperature drops below the Low Limit

Burner turns on and Zone Control is de-energized. Burner turns off

setting minus the differential (if applicable).

and Zone Control is re-energized when the water temperature

 

exceeds the Low Limit setting.

 

 

9

68-0281EFS—05

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Contents Application SpecificationsDOE Compliance and Operation Environmental RatingsInstallation When Installing this ProductMounting New Installation Flush-Mounted Aquastat ReplacementWell-Mounted Aquastat Replacement Replacement Sensor Installation WiringOperation FuseAdjustable Features Adjusting SettingsDisplay DefinitionOperation Anti Short-Cycle FeatureHigh Limit Controller Low Limit and Circulator ControllerCheckout TroubleshootingLine Voltage Indirect Tank Aquastat Zone Request ZR terminal is connected to Time is applied, see TableMinute Cause/Action Alarm LED Error Codes Aquastat EnviraCOMTroubleshooting Guide System Check ActionIf no 120 Vac, replace control ConditionSet ELL to On for External Low Limit see If no 120 Vac, check C1-C2 see aboveTH9421C L7248L multizone system with circulator connections Outdoor Domestic HOT Reset Module L7248L External Low Limit connections Automation and Control Solutions Caractéristiques électriques Caractéristiques TechniquesTion HomologationsMontage Lors de linstallation du produitSerrer fermement la vis de lattache Nouvelle installationLes modèles à montage horizontal Installation du capteur de rechangeFonctionnement CâblageFusible GénéralRéglages AfficheurTableau 3. Caractéristiques réglables Régulateur Limite haute FonctionnementRégulateur de Limite basse et de circulateur Tableau 4. Définitions de la lecture de laffichageZR Demande deau chaude domestique Fonction Anti-court cycleProtection contre le gel Fonctionnement de la purge thermiqueDépannage VérificationLimite de température de purge Thermique Taux de chute de température de purgeMinute ou si le délai de purge thermique tPt a expiré Le thermostat fait une demande de chaleurCycles expire une fois la demande en chaleur satisfaite La température de la chaudière dépasse laMédiaire de la borne ZR Action Réponse du système Diaire de la borne ZR Action Réponse du systèmeCondition liée Système Au diagnostic Vérifier Action AlarmeCodes derreur DEL Aquastat Cause/Action EnviraCOMEst chaude, la La chaudière Lafficheur est 120 V c.a. à C1-C2Pompe Remplacer le régulateurL7224A,C système multizones avec connexions du circulateur Capteur ’EXTÉRIEUR Circulateur L7228l système multizones avec connexions du circulateur ’EXTÉRIEUR Domestique Solutions de régulation et d’automatisation Cumplimiento y funcionamiento de acuerdo con el DOE AplicaciónespecificacionesClasificación eléctrica Parámetros ambientalesInstalación Cuando instale este productoMontaje Instalación Instalación nuevaReemplazo del Aquastat montado en cilindro Reemplazo del Aquastat montado a rasInstalación del sensor de reemplazo Desconecte la energía eléctrica yFuncionamiento CableadoAjuste de las configuraciones PantallaTabla 3. Características regulables Tabla 4. Definiciones de la lectura de la pantalla Controlador de límite máximo FuncionamientoControlador de límite mínimo y circulador Función de ciclo anticortoVerificación Localización Y Solución DE ProblemasSi corresponde Condiciones de error Configuración de límiteÓrdenes de calefacción del TermostatoEl error desaparece automáticamente Condición de errorRendimiento del sistema disminuirá Más de 60 segundosCableado de B1 Err9a Emite una orden de calefacción MáximoReinicio exterior Err 11a 148 EnviraCOM 1, 2, 3, verifique el cableado del sensorCondición de Sistema Diagnóstico Verificación Acción Tabla 11. Guía de localización y solución de problemasSensor Circulador Módulo DE Aquastat DEL Reinicio Exterior Tanque Indirecto ELL=OFF Apagado Panel DE Reproducción Automatización y control desenlace
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