HydroTherm HeatNet KN -6 User Information page 64

DEFAULT SETTINGS & MENU ITEM DESCRIPTIONS
LOW TEMP
TEMP < 40F
MENU
HEAT EXCHANGER
ALARM TYPE
EXCHR DELTA T
LIM-> HALF RATE
SEND RETURN
TEMP DISAB
OFF
40 F 35-200 F
DEFAULT
RANGE
VALUE
FAULT FAULT/WARNING
AUTO AUTO
60 F 1 to 120 F
NA
YES
RETURN RETURN, SYS RET
SYS RET, RETURN,
OFF
OFF
in LOCAL. The boiler will continue to run in LOCAL until
communications are re-established or this entry is set to OFF.
This entry may be set to one of the temperature sensors: SUPPLY,
HEADER, RETURN, or turned OFF (default). If this entry is set to a
sensor and the temperature falls below TEMP, the boiler will
automatically start and run the water temperature up to the LOCAL
Setpoint and then shut OFF.
This is the temperature that the selected sensor must fall below for
the boiler to start.
DESCRIPTION
FAULT will stop the boiler when the Delta T has exceeded its
setting.
WARNING will allow the boiler to continue running, but produce
the Warning message.
Settings are AUTO if running DELTA HIGH/LOW protection.
This is the maximum differential temperature the heat exchanger can
see before the LIMIT RATE feature is activated, and a log entry is
made.
Not Available when operating in DELTA HIGH/LOW protection.
Limit to Half Rate: When set to YES, and the maximum differential
temperature (delta T) has been exceeded, the fire rate called for is cut
in half. In other words: if we are calling for 80% modulation and
have exceeded the delta T, the boiler will only fire at 40%. The delta
T needs to drop 10F below the maximum delta T to reset this limit.
The message ― ½ INPUT‖ will be displayed on a member boiler and
a Master Boiler will display the Modulation % for the system even
though it is running at ½ of this rate. This method helps protect the
heat exchanger from damage due to excessive delta T's. If this
Master boiler is running
This setting is used by the Master boiler to select which Return
sensor temperature to send to all Member boilers. The Return
temperature will then be used by the Member boilers (usually non-
condensing) to determine if they can be called by the Master to run.
If a System Return sensor is available on the Master, set this setting
to SYS RET. If only a Return sensor is available, set to RETURN.
This setting is used by a Member boiler (primarily a non-condensing
type) to determine which return sensor to look at when determining
if it is safe to fire. Its purpose is to keep non-condensing boilers from
firing in a condensing mode.
SYS RET the boiler will use the Return temperature sent from the
MASTER boiler.
RETURN the boiler will use its own Return sensor. If it is set to
OFF, then this feature will not be used.
If a sensor is selected, then the Boiler will determine if the Return
sensor's temperature is below the TEMP< XXX setting in the
following menu. If the Return temperature is lower, the boiler will
take itself offline from the Master. Informing the Master that it can
not run. The message ―blr offline" will be displayed in the Status
HeatNet Control V3 2.x
Page 64