17
Servicing should only be performed by a Quali
fi
ed Service Technician
CIRCULATION PUMPS
DHW Pump Delay
The DHW pump delay parameter sets the length of time the DHW pump (if connected) will run after a DHW
demand has been satis
fi
ed. This parameter is adjustable by the installer by accessing the DHW Pump Delay
parameter. The time range for this parameter is 10 seconds to 40 minutes. The default time is 1 minute.
DHW Anti-Seize
If the water heater pump does not run for 24 hours, it will be turned on brie
fl
y to prevent it from seizing. The
length of time it runs is determined by the DHW Pump Anti-Seize Delay parameter. The range of this setting
is 0 seconds to 50 minutes. The default setting is 20 seconds.
BUILDING MANAGEMENT SYSTEM (BMS)
BMS Tstat Input
When controlling the water heater through the 0 - 10V BMS input or through ModBus, the water heater can
be enabled one of two ways. With the BMS Thermostat Input parameter set to ACTIVE, the water heater will
be enabled by closing the tank thermostat input. When set to INACTIVE, the water heater 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 ModBus. The default value is INACTIVE.
BMS
The set point or modulation of the water heater may be controlled through the 0 - 10V BMS input or through
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. The default value is INACTIVE.
BMS Type
When programmed for BMS control through the 0 - 10V BMS input or through ModBus, 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 tank set point. The default setting is SETPOINT.
Volts at Min
When programmed for BMS control through the 0 - 10V BMS input or through ModBus, 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 10.0V Volts. The default setting is 2.0V.
Volts at Max
When programmed for BMS control through the 0 - 10V BMS input or through ModBus, 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.
Rate at Min Volts
When programmed for BMS control through the 0 - 10V BMS input or through ModBus 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 20%.
Rate at Max Volts
When programmed for BMS control through the 0 - 10V BMS input or through ModBus 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%.
