43
®
Option 5.3 - Bumpless transfer operation (0 - 2)*
This option parameter determines how the modulation rate is affected when
power to the unit
is
interrupted or the
modulation mode
is changed. The options are as follows:
Option 5.4 - Modulation speed (25 - 100%)*
This option allows adjustment of the modulation speed between 25% and 100% of the fastest modu-
lation possible, while still obtaining the correct fuel/air ratio. When not modulating, all drives move
at their maximum speeds.
Option 5.5 - Modulation sensor input type (0 - 3)*
The modulation sensor input is configured to receive a standard 0-5V or 4-20mA signal or a Fireye
fail safe pressure/temperature sensor. When using a Fireye sensor, the unit may be used to monitor
the boiler high safety limit and perform a safety shutdown if it is exceeded. Ensure that the links on
the backplane board are set to correspond with the setting of this option parameter (see Options Link
section for details).
Option 5.6 - Boiler high safety limit (0 - 999[NX1040] / 0.0 - 99.9[NX1030])*
If a Fireye fail safe boiler sensor is used (such as the NX1025, NX1030 or NX1040) and track mod-
ulation input is not selected, the unit may be used to monitor the boiler high safety limit and perform
a shutdown if the limit is exceeded (see Fault Code Listing F41 for details).
Option 5.7 - System modulation units (0 - 3)*
The system modulation units may be selected as shown below.
0
If the burner is fired up in MANUAL mode, the drives remain at low fire until modulated manually.
If the modulation mode is changed from AUTO to MANUAL while the burner is firing, the drives remain at their current posi-
tions.
1
If the burner is fired up in MANUAL mode, the drives are modulated to the last positions used in MANUAL mode.
If the modulation mode is changed from AUTO to MANUAL while the burner is firing, the drives are modulated to the last posi-
tions used in MANUAL mode.
2
The unit powers up in the last selected modulation mode.
If the burner is fired up in MANUAL mode, or the modulation mode is changed from AUTO to MANUAL while the burner is fir-
ing, the drives are modulated to the positions used last time in MANUAL mode.
0
0-5v operation. Set the SENSOR IN link to “V”. Set the SENSOR SUPPLY link as required.
1
4 - 20mA operation. Set the SENSOR IN link to “I”. Set the SENSOR SUPPLY link as required.
2
NX1040 fail safe boiler temperature sensor. Set the SENSOR IN link to “V” and the SENSOR SUPPLY link to +24V.
3
NX1025 and NX1030 fail safe boiler pressure sensors. Set the SENSOR IN link to “V” and the SENSOR SUPPLY link to +24V.
0
PSI - (pounds per square inch)
1
Bar
2
°F
3
°C
