Install Instructions

42
VI: OPERATING (continued)
Call for Heat Circulator Status
T-T
Input
ZR
Input
Priority
Time
()
System
Circulator
Output
DHW
Circulator
ZC Output
on off  on off
on on  off on
off on  off on
on off  on off
on on  on on
off on  off on
TABLE 9: DOMESTIC HOT WATER DEMAND,
(PARAMETER = )
Call for
Heat
ZC and ZR
Terminal
Function
()
Boiler
Temp.
Boiler Status,
(B1 Output)
TT= on -- < 140 Start with no delay
TT = on -- >140 Start after 2 minute delay
ZR = on  =  <140 Start with no delay
ZR = on  =  >140 Start after 2 minute delay
ZR = on  =  <140 Start with no delay
ZR = on  =  >140 Start with no delay
TABLE 8: CIRCULATOR PRE-PURGE TIME EXAMPLE,
PARAMETER PP_= 2 MINUTES
terminal for the DHW Circulator. When there
is a DHW call for heat, the System Circulator
is “forced off”, the DHW Circulator terminal
is energized and the circulator pre-purge
time delay control logic is bypassed to allow
the boiler to re without delay. When DHW
demand ends the System Circulator “force
off” is removed, the circulator can respond
normally, and the DHW Circulator is de-
energized. The DHW call for heat is detected
by a voltage on to the "ZR" terminal. When
a Priority Time parameter is set to “off” the
System Circulator is not forced off for a DHW
call for heat. Refer to Table 9.
g. Start Temperature ()
The amount of “Heat available” is calculated by
taking the difference between measured boiler water
temperature and the Start Temperature setting.
Useful “Heat Available” is dependent on the type of
heating emitter installed in the home. Heat emitters
require a certain minimum temperature to operate
effectively. Our default settings reect cast iron
radiators. Fan Coils may require a start temperature
setting of 180°F or 160°F before providing heat
to the home. The Start Temperature has a factory
setting of 140°F and is eld adjustable between
140°F and 180°F.
h. Priority Time ()
When the Priority Time parameter is set to “on”
and Domestic Hot Water (DHW) call for heat is
“on” the DHW demand will take “Priority” over
home heating demand and the system circulator
will be forced “off”. Priority Time ends and the
system circulator is released to service home heating
demand when Domestic Hot Water call for heat is
over. When Priority Time parameter is set to “Off”
the DHW call for heat does not force “off” the system
circulator. The Priority Time has a factory setting
of “On” and is eld adjustable between “On” and
“Off” Refer to Table 9.
i. ZC and ZR Terminal Function ()
The boiler control allows conguration of the ZC
output functionality to help the CL integrate into
each installation more effectively. The ZC output
can be connected to a domestic hot water circulator
or a second heating zone circulator or be used to
enable pumps in a warm start application. These
applications are selected as follows:
i. When  is set equal to Domestic Hot Water
Demand ()
When there is an Indirect Water Heater (IWH)
the boiler control provides a “ZR” input
terminal for the IWH Aquastat and “ZC” output
ii. When  is set equal to Zone Request ()
When there is no IWH the Cold Start Boiler
Control “ZC” output may be configured
to control a second heating zone. This is
particularly helpful when the home uses only
two heating zones. The boiler control replaces
the need for a two circulator zone panel. When
DHW Terminal Function () is set to 
the boiler control’s two circulator outputs are
used to control two independent heating zones.
Refer to Table 10. A "TT" input causes a call
for heat and energizes the System Circulator
output to service heating zone 1. A second
zone’s thermostat may be wired to the "ZR"
input to energize heating zone 2 circulator wired
to the "ZC" output. Both outputs function
independently, "TT" input controls only the
System Circulator output and the "ZR" input
controls only the "ZC" output. Both inputs
cause a boiler call for heat.
The Warm Start Boiler Control with set
equal to Zone Request () energizes the "ZC"
terminal while the boiler is warm as described
earlier in this section (refer to Paragraph A,2,f).
The "ZR" input is a call for heat that starts the
boiler.