Camus Hydronics DFH1100 Installation, Operation And Service Manual - page 28
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in the electrical enclosure across the contacts to be used
for connection to the remote operator. The fixed auto re-set
limit is set to 230°F. In addition to the auto reset limit the
factory installs a manual re-set limit set to 250°F. The
control provides pump operation. Staging operation is
provided by an external sequencing control. Heat demand
is provided to the external sequencing control. External
sequencing control then provides heat demand to the
control. Each control turns on its respective appliance pump
and stage 1 contact whenever an external heat demand is
present. Once the external heat demand is removed from
the control, the control turns off the stage 1 contact and
operates the pump to provide purging. Once the purge
period is complete, the control turns off the appliance
pump.
CAUTION
If this setting is inadvertently chosen the appliance will
cycle on the limits. There is a danger of scalding if this
setting is used in a DHW application.
6.2 MODULATING
SIGNAL
GENERATOR
This controller is located below the appliance temperature
controller. Once a call for heat has been initiated by the
appliance temperature controller this control generates a
modulating signal (4 – 20 mA or 2 – 10 VDC) based on
return water temperature. After completion of factory
settings the lock feature permits adjustment of set point
only (SV). This setting is normally 5ºF below the appliance
temperature controller setting. In this way the firing rate of
the boiler will be at minimum when return water
temperature is 5ºF below target. The modulating signal
generator has separate settings for domestic and hydronics
applications and is factory set as shown below:
Table 13
DOMESTIC
HOT
WATER
HYDRONIC
HEATING
P-n1 0
0
P-n2 1.0
1.0
P-df 1.0
1.0
P-SL 32
32
P-SU 160
220
LOC FEATURE:
1 - locks in all settings
0 - allows adjustments to all settings
2 - allows adjustment of set point only
6.3
VARIABLE FREQUENCY DRIVE (VFD)
The VFD has a factory set security code which has to be
entered before any adjustments can be made. The VFD
has 50 parameters, which can be adjusted. At present only
the following are pertinent:
Table 14
Parameter
#
Function Settings
2 Carrier
Frequency
03
4 Stop
Method 03
5 Standard
Speed
Source
04 (03 for 2- 10
VDC)
19
Acceleration Time
120 sec
20
Deceleration Time
60 sec
28 Fixed
Boost
1.0
36 Preset
Speed 29
38 Skip
Bandwidth 3.0
45
Speed at Minimum
Signal
32 (25 for
condensing)
50
Fault History
View Only
51 thru 58
Miscellaneous
View Only
PART 7
COMPONENTS
7.1
HOT SURFACE IGNITER (GLOW BAR)
The silicon carbide igniter is inserted directly through the
fan flange and held in place by two screws. A hold down
bracket as well as sealing gasket above and below the
igniter assures a good seal. Care must be taken when
removing and/or installing the igniter since the silicon
carbide element is brittle. Always remove the igniter prior to
removing the fan assembly for inspection of the burner and
heat exchanger. Properly prepared igniter will have a bead
of silicone sealing the end mounting bracket to the ceramic
shaft.
Figure 18 – Hot Surface Igniter
During trial for ignition a properly operating igniter will
generate 3A which is the proof current required by the
ignition module for reliable and consistent operation. It is
recommended that the hot surface igniter be replaced every
4,000 hours of appliance operation to maintain peak ignition
efficiency.
7.2
FLAME SENSOR
The flame sensor is inserted directly through the fan flange
and is screwed into the fan flange. Care must be taken,
when installing the flame sensor, to align it perpendicular to
the fan flange and parallel to the burner tube and not to
over tighten. Always remove the flame sensor prior to
removing the fan assembly for inspection of the burner and
heat exchanger.
Figure 19 – Flame Sensor