Camus Hydronics DFH1100 Installation, Operation And Service Manual - page 5
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1.4
WHAT THE LIGHTS MEAN ON YOUR
CAMUS APPLIANCE
• POWER
Light off means there is no power
to the appliance.
• OPERATOR Light on indicates demand for
operation (temperature or external
control).
• HIGH
LIMIT Light off means high limit on back
of unit tripped.
• WATER
FLOW
Light off means no flow/low water
level or defective flow switch/low
water cutoff.
• AIR
FLOW
Light off means problem with
combustion fan, dirty air filter,
blocked vent or fan shut off after
10 minutes in flame failure. If
optional low and/or high gas
pressure switches are provided it
may mean that the appliance has
shut off on a gas pressure
condition.
• IGNITION
TRIAL
Light comes on only during start
up trials (3 trials standard and
single trial for CSD1, for CSD1; to
reset push and hold reset button
on front of electrical panel until red
LED is lit on ignition control).
• MAIN
FLAME Lit only when ratio control valve is
energized. Valve will open only if
proof of closure switch is closed.
Indicator in view window shows
position of valve stem. Light will
stay on only if burner is firing.
• FLAME
FAILURE
May momentarily light up during
ignition trials. If appliance fails to
start the fan will shut down, the air
flow light will go out and the flame
failure light will stay on
continuously.
** If the series of lights stops during start up, the next
light that is NOT lit identifies where the problem is.
1.5
HOW IT OPERATES (SEQUENCE OF
OPERATION)
1
The power switch is placed in the “ON” position.
2
Minimum 120 VAC 60hz single phase (15A circuit) is
supplied to the control junction box models DF-500
through DF-2000 and 120 VAC (20A circuit ) models
DF-2500 thru DF-3000 and 120/230 VAC 60hz single
phase (20A circuit) models DF-3500 through DF-4000
and 120/230 VAC 60hz single phase (30A circuit)
models DF-4500 through DF-5000.
3
120 VAC power is supplied to the control transformer
and Ignition Module on all models.
4
24 VAC is supplied to all low voltage controls for all
models.
5
After the appliance water pump starts, flow is proven
by the flow switch. The low water cutoff and flow switch
are shipped loose .The flow switch is to be mounted in
a tee at the outlet of the appliance. Take care to
properly trim the flow switch paddles so as not to jam
the switch in the tee. The normally open dry contacts in
the low water cutoff (LWCO) are to be wired in series
with the normally open contacts of the flow switch.
Locate the probe type LWCO in the piping 2 to 3 feet
above the boiler inlet/outlet connection. In all cases
check with local codes.
6
Local or remote operator calls for heat and operator
light illuminates. If the appliance is provided with a
local remote switch the local control settings are to be
set above the normal maximum expected return water
temperature. In this way the local control will not
interfere with normal operation of the remote operator
and will prevent the appliance from cycling on its limit if
the appliance is switched over to local operation due to
a failure in the remote operating system.
7
The local thermostat initiates a start-up sequence once
it receives a heat demand. If the appliance is equipped
with a local/remote switch and if the switch is set in
remote, a heat demand is available only if the remote
system calls for heat.
8
The local thermostat energizes the motor stop/start
relay which closes the initiate contacts to the variable
frequency drive (VFD) which starts to ramp up the
frequency to the 230V 3 phase motor of the
combustion fan. If the VFD is not in fault mode the
frequency will accelerate at the preprogrammed rate
towards 60 HZ using the modulating signal provided by
the on board modulating control or the remote
operating system if a local/remote switch is provided.
9
If limit, water flow and airflow lights are lit, the ignition
module will receive a 24V signal at terminal ‘TH‘ thru a
purple wire. After performing internal self checks the
ignition module will energize the amber trial for ignition
light and the hot surface igniter at S1 thru a black and
brown wire respectively and close the auxiliary fan
connections thru two blue wires which will switch a
20Wresistor across the modulating signal. This will
occur whether the appliance is in remote or local
mode. The resistor will case the VFD to see a
minimum modulating signal and cause the fan motor to
decelerate to the frequency programmed for soft start.
The ignition control looks for the set proof current from
the igniter (2.7 A +/-0.2).
10 If the proof current is not reached the module will stop
the ignition sequence after the trial for ignition .The
blue main flame light indicating that the main valve is
energized will not come on and the appliance will go
into lockout. If the proof current is reached the ignition
module sends a 24V signal thru a blue wire marked
‘valve” to the 24/115V interface relay and to the proof
demand terminal 3 on the on board smart flame
control.
11 115V from the 24/115V interface relay will only reach
the ratio control valve if the proof of closure (POC)
switch in the ratio control valve is closed .If the switch
is in an open position the valve stem travel indicator
visible thru a view window in the valve will not move
even though the blue main flame light will illuminate.
This can occur if there is dirt under the valve seat or if
the POC switch is defective.
12 If the POC switch is initially closed, the blue main flame
light will illuminate and the latching relay located in the
lower end of the control box allows the 115V signal to
the control valve to be uninterrupted when the control
valve drives open and the POC switch contacts open.
13 After the valve open time (7 or 10 seconds) is ended
the ignition module looks for a minimum flame
rectification signal of 2 µA DC from the flame sensor. If
the signal is present the ignition module will allow the
control valve to remain open, if the ignition module
does not see a continuous signal it will shut down the