Camus Hydronics DRH1000 Installation, Operation And Service Manual - page 52
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PART 8
FIELD STARTUP
PROCEDURE
8.1
CHECKING THE INSTALLATION
•
Inspect the connections for water, gas and electricity.
•
Confirm that water is being pumped toward the heat
exchanger inlet. Never pump away from the exchanger
since this will result in a low-pressure zone, which will
allow localized boiling and result in heat exchanger
damage.
•
Power to the boiler and pump must be from the same
circuit to prevent the boiler firing in case the pump is
inadvertently shut off.
•
Inlet gas pressure must be a minimum of 3” W.C. for
natural gas and 11” W.C. for propane.
•
With the boiler off, open the main gas supply valve and
vent the trapped air from the piping leading to the boiler.
Confirm that all gas connections to the heater are tight and
that there are no missing test plugs.
•
DR2000 – 5000: Connect a manometer to obtain the
differential air pressure between negative and positive
ports, see Figure 10.
•
The air/gas ratio controller automatically adjusts to match
the air signal on the gas side. In this way true mass flow
control of air/gas mix is achieved. All boilers are test fired
and factory set. A test sticker with actual reading is affixed
to the unit.
8.2
CHECKING THE CONSTRUC
TION
•
Check the boiler wiring to see that it agrees with the wiring
diagram supplied.
•
Confirm that all terminal strips and field connections are
identified.
•
Confirm that the Dynaforce® controller is set in the proper
mode. Auto reset limits are fixed in all modes.
•
With the firing valve in the off position, switch on power to
the boiler. The fan motor will accelerate until the airflow
icon becomes green.
•
Once all lights past the STAT are green the SOLA will try
for ignition. When the igniter is hot enough, the gas valve
actuator is energized and if ignition is accomplished the
Burner State will show “Run”. If ignition is not
accomplished, the Burner State will show “Safe Startup”
and two more ignition trials will be made 15 seconds apart.
The control will then proceed to lockout and must be reset
by momentarily interrupting power. It is normal during
initial start up, when air is being purged from the piping, to
require two to three tries before successful ignition.
•
With the boiler running, check for flue gas leaks along the
inner cabinet joints and around the flue outlet.
•
Repair any leaks prior to the next step.
•
At the factory adjustments were made to achieve proper
input and acceptable burner performance at full input and
at minimum input.
•
Depending on field conditions, the CO
2
metering valve
may require some minor adjustment at full input. Refer to
Table 14. Adjustment at minimum input can be done at the
low fire adjustment screw by first removing the brass cap.
Turning adjustment screw clockwise will increase CO
2
.
8.3
GAS VALVE ADJUSTMENT PROCEDURE
Table 14: Combustion Values
Dynaforce® Combustion Values
Natural Gas
Propane
CO
2
CO
CO
2
CO
Max.
Fire
8.5% - 9.0%
PPM
9.5% - 10.0%
PPM
Min.
Fire
8.0% - 8.5%
PPM
9.0% - 9.5%
PPM
If adjustment of the gas valve is required use the following
procedure.
It is imperative that the coldest system water temperature
possible is used when setting up low fire combustion.
These cold system temperatures create large amounts of
flue condensate resulting in large amounts of condensate
build up on the stainless steel finned heat transfer tubes.
These conditions create the highest back pressure
through the boiler and makes for the most critical
combustion set up point when running 20% input. This set
up must be achieved quickly to ensure low system
temperatures are maintained throughout the set up of
single or multiple boiler installations.
Light off the boiler at low fire and make the initial
adjustment to the low fire bias to obtain the specified CO2,
CO, at 20% gas input.
While maintaining the lowest possible water temperature,
observe the differential gas pressure. The differential gas
pressure must not drop below a minimum of 0.25” w.c. If
necessary increase the VFD (Hz) setting until this
pressure is met. Once the boiler has run for at least 10-15
minutes with dead cold water, there should be a maximum
amount of condensate in the lower heat exchanger. At this
point adjust the combustion for CO2.
The boiler must continue to run with stable combustion
without making any howling noise which usually happens
from an overly rich mixture. Once settings are complete at
low fire, continue to run the machine for at least 10-15
more minutes and record the final low fire input and the
combustion data.
To ensure the coldest possible water temperatures for set
up on multiple boiler systems, the low fire combustion
should be established on all boilers before setting any
boiler high fire combustion rates.
In order to perform adjustments to the gas valve the
Dynaforce® must be firing before proceeding.
Figure 32: DR 300 – 400 Gas Valve
High fire air/gas ratio adjustment
(use slotted screwdriver for
adjustment, counter-clockwise
increases CO
2
)
Low fire air/gas ratio adjustment
(use T-40 for adjustment,
clockwise increases CO
2
)