Lochinvar FTxl 500 Service Manual page 28

1
Service
Building Management System (BMS)
BMS
The set point or modulation of the boiler may be controlled
through the 0 - 10V BMS input, BACnet, or ModBus. When
the BMS parameter is set to INACTIVE, the 0 - 10V input will
be ignored. When set to ACTIVE, the set point or modulation
will be controlled by the voltage on the 0 - 10V input (in
the case of 0 - 10V BMS control), or the 0 - 10V input value
received through ModBus or BACnet. The default value is
INACTIVE.
BMS Type
When programmed for BMS control through the 0 - 10V BMS
input or through ModBus/BACnet, the 0 - 10V signal can be
interpreted as either a modulation command or a set point.
When the BMS Type parameter is set to POWER, the 0 - 10V
signal will control the modulation. When set to SETPOINT,
the 0 - 10V signal will control the SH set point. The default
setting is SETPOINT.
Rate at Minimum Volts
When programmed for BMS control through the 0 - 10V
BMS input or through ModBus/BACnet and the BMS Type
is programmed as POWER, the modulation percentage
represented by the Volts at Minimum parameter is set by the
Rate at Minimum Volts parameter. The minimum value is 0%
and the maximum is the Rate at Maximum Volts setting. The
default value is model dependant.
Rate at Maximum Volts
When programmed for BMS control through the 0 - 10V
BMS input or through ModBus/BACnet and the BMS Type
is programmed as POWER, the modulation percentage
represented by the Volts at Maximum parameter is set by the
Rate at Maximum Volts parameter. The minimum value is the
Rate at Minimum Volts setting and the maximum is 100%. The
default value is 100%.
Set Point at Minimum Volts
When programmed for BMS control through the 0 - 10V
BMS input or through ModBus/BACnet and the BMS Type is
programmed as SETPOINT, the set point represented by the
Volts at Minimum parameter is set by the Set Point at Minimum
Volts parameter. The minimum value is 32°F (0°C) and the
maximum is the Set Point at Maximum Volts setting. The
default value is 70°F (21°C).
Set Point at Maximum Volts
When programmed for BMS control through the 0 - 10V
BMS input or through ModBus/BACnet and the BMS Type
is programmed as SETPOINT, the set point represented by
the Volts at Maximum parameter is set by the Set Point at
Maximum Volts parameter. The minimum value is the Set
Point at Minimum Volts setting and the maximum is 190°F
(88°C). The default value is 180°F (82°C).
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Service Manual
Volts at Minimum
When programmed for BMS control through the 0 -
10V BMS input or through ModBus/BACnet, the Volts at
Minimum parameter should be set to the minimum voltage
signal sent to the SMART SYSTEM control. The range of
this parameter is 0.0V to the Volts at Maximum value. The
default setting is 2.0V.
Volts at Maximum
When programmed for BMS control through the 0 -
10V BMS input or through ModBus/BACnet, the Volts at
Maximum parameter should be set to the maximum voltage
signal sent to the SMART SYSTEM control. The range of
this parameter is the Volts at Minimum value to 10.0V. The
default value is 10.0V.
BMS Thermostat Input
When controlling the boiler through the 0 - 10V BMS
input, BACnet, or ModBus, the boiler can be enabled one
of two ways. With the BMS Thermostat Input parameter set
to ACTIVE, the boiler will be enabled by closing the Heat/
Loop Demand 1 input. When set to INACTIVE, the boiler
will be enabled by the voltage level on the 0 - 10V input (in
the case of 0 - 10V BMS control), or the 0 - 10V input value
received through BACnet or ModBus. The default value is
INACTIVE.
On Volts
When programmed for BMS control through the 0 -
10V BMS input or through ModBus/BACnet and the
BMS Thermostat Input is set to INACTIVE, the On Volts
parameter determines the 0 - 10V BMS input voltage at
which the boiler is enabled. The minimum value is 0.5V and
the maximum is 10.0V. The default value is 2.0V.
Off Differential Volts
When programmed for BMS control through the 0 - 10V
BMS input or through ModBus/BACnet and the BMS
Thermostat Input is set to INACTIVE, the Off Differential
Volts parameter determines how far below the On Volts
setting the 0 - 10V BMS input voltage must be in order
to disable the boiler. The minimum value is 0.2V and the
maximum is the On Volts setting. The default value is 1.0V.
ModBus/BACnet
When BMS is set to ACTIVE (see BMS Active / Inactive) and
the boiler is being controlled through BACnet or ModBus,
set ModBus/BACnet parameter to ACTIVE. Otherwise, set
the ModBus/BACnet parameter to INACTIVE. Note that
the boiler can still be monitored by ModBus or BACnet
with this parameter set to INACTIVE. The default value is
INACTIVE.