High Limit Controller - Honeywell L7224U Instrucciones De Instalación

L7224U OIL ELECTRONIC AQUASTAT
Text
Description
Err Error Code (if one is present)
bt Boiler Temperature
HL High Limit
1
HdF High Limit Differential
LL Low Limit (L7224 only)
Low Limit Differential (L7224 only)
Ldf
Local Thermostat Status
tt
EnviraCOM Thermostat Status
ttE
B1 (Burner) output (ON or OFF)
brn
C1 (Circulator) output (ON or OFF)
Cir
ZC (Zone Control) output (ON or OFF)
ZC
ZR (Zone Request) Call for HEAT (ON or OFF)
Zr
ELL External Low Limit Enabled (L7248L only)
duu ZR Configured as Domestic Hot Water
Request (L7224, L7248L only)
ASC Anti Short-Cycle Timeout
bSP Boiler Setpoint
2
dhc
DHW Module Connected (YES or NO)
3
ot Outdoor Temperature
2
otL Outdoor Temperature Low
2
otH Outdoor Temperature High
2
btL Boiler Temperature Low
2
bP Boost Period
2
bS
Boost Step
2
Warm Weather Shutdown Temperature
UUS
2
°F
Units are displayed in degrees Fahrenheit
°C
Units are displayed in degrees Celsius
OFF
Input or Output is OFF
Input or Output is ON
On
DISPLAY SHOWS LOCAL SETTING; NOT THE SETTING
1
AS MODIFIED BY AN EXTERNAL ENVIRACOM CONTROL.
SETTINGS ARE VIEWABLE ONLY IF THE OUTDOOR
2
RESET MODULE AND OUTDOOR TEMPERATURE
SENSOR ARE INSTALLED AND FUNCTIONING PROPERLY.
SETTINGS ARE VIEWABLE ONLY IF THE DOMESTIC
3
HOT WATER MODULE AND SENSOR ARE INSTALLED
AND FUNCTIONING PROPERLY.
Fig. 7. Explanation of display readout.
*Settings viewable on the 3-digit display only if the
"Outdoor Reset Module" is installed.
69-1720EFS—01
®
CONTROLLER
Operation
Display
The L7224U can be in any of four operational states:
Shows
Normal, High Limit, Low Limit and Error. The controller
moves back and forth from High Limit to Normal to Low
Limit state as part of normal operation. The operating
states are:
1. Normal: Boiler temperature went below the High
2. High Limit: Boiler temperature went above the High
3. Low Limit: Boiler temperature went below the Low
4. Error: The controller has detected an error condition
The operating sequence for the L7224U is shown in Table
3.

High Limit Controller

The High Limit opens and turns off the burner when the
water temperature reaches the setpoint. The High Limit
automatically resets after the water temperature drops
past the setpoint and through the adjustable Differential.
Low Limit and Circulator Controller
On a temperature rise, the burner circuit breaks and the
circulator circuit makes (assuming no call for heat is
present) at the Low Limit setpoint. On a temperature drop
of 10° F (6° C) below the Low Limit setpoint (with the
adjustable Differential at the minimum setting of 10° F
(6° C)), the burner circuit makes and the circulator circuit
breaks. Refer to Fig. 7.
HIGH LIMIT
SETTING
LOW LIMIT
SETTING
M29552
1
6
Limit setting (minus the Differential) and has not
exceeded the High Limit setting; or, the boiler tem-
perature went above the Low Limit setting and has
not gone below the Low Limit setting (minus the Dif-
ferential).
Limit setting and has not dropped below the High
Limit setting (minus the Differential).
Limit setting (minus the Low Limit Differential) and
has not gone above the Low Limit setting.
(e.g., open sensor) and has shut down the burner
output. The Zone Control (ZC) output is energized.
The controller continues to monitor the system and
automatically restarts if the error condition clears.
Refer to Table 4–6.
10ºF (6ºC)
DIFFERENCE
10ºF (6ºC)
DIFFERENCE
WHEN WATER REACHES LOW LIMIT SETTING, THE BURNER SHUTS
OFF OR THE CIRCULATOR PUMP STARTS (WHEN CALLING FOR HEAT).
Fig. 8. Setpoints and differentials.
SWITCH BREAKS ON
TEMPERATURE RISE.
BURNER TURNS OFF.
CIRCULATOR OPERATES
ON A CALL FOR HEAT.
SWITCH MAKES ON
TEMPERATURE FALL.
BURNER OPERATES ON A
CALL FOR HEAT.
WITH NO HEATING
DEMAND, SWITCH BREAKS
ON TEMPERATURE RISE.
1
SWITCH MAKES ON
TEMPERATURE FALL,
BURNER IS ON TO
MAINTAIN MINIMUM
WATER TEMPERATURE.
CIRCULATOR IS OFF.
M23365