LAARS Heating Systems
Page 44
Section 9
SetUP anD ConfIGUratIon
9.1
review of lead/lag Control
System
9.1.1
about lead/lag operation
The boilers in this series are always set up for Lead/
Lag operation. In a single-boiler installation, there
are two controllers and two burners, as shown in Fig.
49. The controller for the upper burner is set up as
the Primary control. For control purposes, this is
the Lead/Lag Master and also operates as Lead/Lag
Slave 1. The control for the lower burner is set up
as the Secondary control and operates as Lead/Lag
Slave 2.
On a multiple-boiler installation, each individual
boiler is still set up as shown in Fig. 49. The boiler
controls are arranged in a “daisy chain” using a
Modbus connection, with the Secondary control
of one boiler connected to the Primary control of
the next boiler. Up to four boilers, with up to eight
controllers, can be connected in this way. See Fig.
50.
fig. 49 – lead/lag arrangement in a Single-Boiler
fig. 50 – lead/lag arrangement in a multiple-Boiler
Primary
burner
Primary
controller
Gas
valve
Gas
valve
Secondary
controller
Secondary
burner
Operator
interface
Boiler 1
Operator
interface
Boiler 1
Slave 4
Boiler 2
Slave 3
Slave 2
Lead Lag
Master and
Slave 1
Slave 6
Boiler 3
Slave 5
Slave 8
Boiler 4
Slave 7
Addr
1
Addr
2
Addr
3
Addr
4
Addr
5
Addr
6
Addr
7
Addr
8
Summary of Contents for NTV1000
Page 2: ......
Page 35: ...NeoTherm Boilers and Water Heaters Page 31 Fig 20 Ladder Diagram...
Page 36: ...LAARS Heating Systems Page 32 Fig 21 Wiring Diagram...
Page 37: ...NeoTherm Boilers and Water Heaters Page 33...
Page 51: ...NeoTherm Boilers and Water Heaters Page 47 Fig 52 Connection Terminals...
Page 130: ...LAARS Heating Systems Page 126 Fig 140 Machine Frame and Rear Panel 13 3 PARTS ILLUSTRATIONS...
Page 131: ...NeoTherm Boilers and Water Heaters Page 127 Fig 141 Front Panel and Covers...
Page 132: ...LAARS Heating Systems Page 128 Fig 142 Burners and Combustion Chambers...
Page 134: ...LAARS Heating Systems Page 130 Fig 145 Electronic Components...
Page 135: ...NeoTherm Boilers and Water Heaters Page 131 Fig 146 Condensate Trap Fig 147 Control Bezel...
Page 136: ...LAARS Heating Systems Page 132 Fig 148 Flow Switch...
Page 137: ...NeoTherm Boilers and Water Heaters Page 133 This page intentionally left blank...