Circulator Pump Options - HydroTherm HeatNet KN -6 User Information

OPTIONAL FEATURES

Circulator Pump Options

There are provisions for a system pump(s) and a local pump.
This is to allow for primary/secondary loop configurations.
The system circulator pump is implemented using the K4,
K13 RELAY and normally open contacts at J13 SYSTEM
PUMP 1 and SYSTEM PUMP 2.
The pumps require motor contactors to isolate
the on-board relay contacts. The on-board
relays should never be used to energize large
pumps directly. Figure 25 illustrates the
connections without contactors for illustrative
purpose.
Figure 24 System Pump connections
System Flow
Prove Switch
System
Pump 1
System
Pump 2
Figure 25
The system circulator pump is supported by (2) modes and
special features.
1. The first mode will allow the circulator pump to remain
on, unless the control's outside high air temperature
setting has been met when using OUTDOOR AIR
RESET.
2. The second mode will allow the circulator pump to be
turned on whenever there is a call for heat (any control
input). This mode will stop the circulator pump when the
call for heat is lost and the pump post purge time has
been satisfied.
The summer pump jog is a special feature that can be selected
when the system is in summer shutdown (OUTDOOR
RESET). The jog allows the system circulator pump(s) and
the local pump to run for the system pump purge time once a
week. It can be set to any day of the week and will occur at
K4
12:01 AM. If (2) system pumps are present, and after the first
pump finishes its post purge, the second one will start and the
K13
first one will stop.
The system flow proving switch is implemented using
SPARE 3/System Water Flow on J11A. If a flow switch is
connected to the WTR FLW interlock, the HeatNet control
will wait up to 10 seconds to prove flow. If flow is interrupted
after it has been established, an error will be displayed and the
boiler will cycle OFF. As long as there is a call for heat,
every 10 minutes the circulator pump will try to re-establish
flow and start the boiler again.
When (2) system pumps are present and flow is not
established or is lost (2) things will occur to try and keep heat
in the system.
1. When first starting a system: If after a 10 second
wait to establish flow has failed, the first pump will
change to the second pump. The second pump will now
try to establish flow for 10 more seconds. If the second
pump fails to establish flow, the HeatNet control waits
10 minutes. After the 10 minutes has expired, the
control now starts with the second pump and attempts
to prove flow for 10 more seconds. If flow does not
Local & DHW Pump connections
Local Pump/Valve
Normally Closed &
Normally Open Contacts
HeatNet Control V3 2.x
DHW
Normally Closed &
Normally Open Contacts
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