LAARS NeoTherm LC NTV1700 - Install and Operating Manual - Manual (Page 119)

NeoTherm LC Boilers and Water Heaters Page 115
12.8 Control Snapshot
The software allows you to take a “snapshot” of
the current state of the controller, including setup
information and operating information. This
information can be helpful during troubleshooting.
How to get there –
Home Page <Setup button> Setup Screen <Control
Snapshot button> Control Snapshot Screen
Figure 138 shows the Control Snapshot screen.
Fig. 138 - Control Snapshot List Screen
Select one of the controllers listed on the right side
of the screen. Press one of the buttons below the
right column to see the snapshot. See Fig. 139.
Fig. 139 - Typical Control Snapshot
The Show Status button captures the current status
of the I/O of the control only. Show Configuration
captures the current parameter settings and the
control setup. You can save the snapshot, give it a
name, or send a copy to the USB port.
12.9 Operating Sequence
Initiation
Each controller enters the Initiation sequence after
one of these conditions:
• Initial power up
• Voltage fluctuations vary +10% or -15%
• Frequency fluctuations vary ±10%
• The demand, limit control input, or TT signals
are interrupted during the prepurge period.
• After the Reset button is pressed.
• After a Fault is cleared using the displays.
The Initiation sequence also delays the boiler
demand from being energized and re-energized from
an intermittent AC line input or control input. If
an AC problem exists for more than 240 seconds, a
lockout will occur.
Start-Up Checks in a Lead/Lag System
For an explanation of Lead/Lag operation, see the
first part of Section 9. In this section, we will focus
on the aspects of Lead/Lag that might be helpful in
troubleshooting.
When a Lead/Lag system is first powered up, the
controller acting as the Lead/Lag Master goes
through a “synchronization” process. During
synchronization, the controller establishes
communications with each of the Slave controllers
via the Modbus link. The Slave controllers
download some setup parameters and operating
history information. (On a system with several
boilers, this phase can take several minutes.) If the
Master cannot establish communications with one of
the Slaves, it triggers a Hold or Lockout.
The Master also checks the status of each of the flap
valves. If the Master cannot determine whether a
flap valve is open or closed, or if it cannot locate the
correct number of flap valves, it triggers a lockout or
hold.
If the system passes the checks described above,
each of the individual controller and burner
combinations is free to operate in the normal
way. The self-check and firing sequence for each
individual controller and burner combination is
described in the following section.