OPTIONAL FEATURES HeatNet Control V3
Page 56
Base Loading, Relay Control
The control has the ability to control (1) base load boiler
using the K8 Relay contacts on J4 pins 2 & 6. In order to
connect to this plug, (2) wires with pins are required and
inserted in J4. Base Loading via relay requires these (2) flying
leads (loose wires available from the factory) to be inserted
into J4, pins 2 & 6. These (2) wires then make up the
Normally Open contacts. This feature also can be used on
Master or Member boilers. The solid state relay K8, with
contact connections on J4.2 & J4.6 has a rating of: 0.1 to 1
Amp.
If the base load boiler is of the modulating type, a 4-20 mA
signal is also provided on J4 pins 1 and 5. Jumper shunt JS1
will then need to be set to 4-20 mA position. Two additional
wires (available from the factory) will need to be added to the
J4 pins at 1 & 5. Pin 1 is the + output of the 4-20 mA
transmitter, and pin 5 is the – output. This modulating control
signal is used to modulate the base load boiler along with the
HeatNet boilers in parallel. The ADAPTIVE MOD does not
function in lowering the modulation rate when the base load
boiler is added. The PID will adapt to the newly fired base
load boiler and lower its modulation rate when the increase in
water temperature is observed.
The Master boiler requires a heat demand input in order to
control a Base Load boiler connected to it. Though, the
Master boiler does not need to be running. This is to ensure
that the system pump and damper will be enabled for the
system. The System pump and Damper control are the main
reasons to connect the Base Load boiler to the Master.
A Member boiler does not need to be firing in order to enable
its Base Load boiler. Provisions for the Base Load boiler
should be checked to allow a system pump to run and any
dampers to open.
Failsafe on the Master boiler will occur if there is a Heat
Demand input present, there are no available boilers to fire,
and the Master has failed.
Failsafe using the Base Load boiler from the Member is
automatic. Whenever the Member fails, the Base Load boiler
will be enabled as long as the Member can do so.
Base loading a Futera II boiler
Enable the base load feature by setting:
1. SETTINGS: BOILER TYPE: OPTION to BASE
LOAD. This setting uses the OPTION Relay K8 (J4 pins
2 & 6) as control for a Base Load Boiler.
2. The SETTINGS: BASE LOADING: BOILERS: to 1.
Currently allows (1) base load boiler.
3. The START WHEN: & STOP WHEN: qualifier
condition to the method discussed below.
4. The DELAY TIME to the amount of time required after
the start qualifier condition has been met to start the
boiler.
If a MINIMUM OFF time of the Base Load boiler is needed,
the Base Load boiler will share the MIN OFF TIME of the
boiler controlling it. If the base load boiler was running and
shuts off, the MIN OFF TIME will need to expire before the
boiler can start again. Once this time expires, the DELAY
TIME also needs to expire to start the boiler. This will help in
minimizing short cycle conditions and can be set at
SETTINGS: FIRING MODE: MIN OFF TIME.
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