Camus Hydronics Dynaforce Series, Installation And Service Manual, Page: 24 / 82

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PART 5 ELECTRICAL & CONTROLS
IT IS EXTREMELY IMPORTANT THAT THIS UNIT BE
PROPERLY GROUNDED!
5.1 ELECTRICAL CONECTIONS
Table 10: Minimum Power Requirements
Model
Voltage
Requirement
Maximum Over
Current
Protection
Full Load
Amps
[Amperes] [Amperes]
300 -
1000
120VAC, 60Hz 20 < 12.0
1200 -
2000
120VAC, 60Hz 20 14.0
2500 120VAC, 60Hz 30 18.0
3000 -
3500
208/230VAC,
60Hz*
30 20.0
4000 -
5000
208/230VAC, 60Hz,
3 Phase**
30 18.0
*This is a 4-wire power supply requiring two (2) lives, a neutral
and a ground
**This is a 5-wire power supply requiring three (3) lives, a neutral
and a ground
Dynaforce® boilers supplied at 460/3/60 voltage, differ from the
standard unit per the following:
CAUTION!
While working with 460V circuits it is imperative that extra
precautions be taken
- Ensure that lock-out/ tag-out procedures are strictly enforced
- Only properly trained and authorized personnel should be
permitted to work on live electrical circuits
- All electrical workers should be trained in electrical rescue
techniques and CPR
Each unit has an internal factory mounted 500VA transformer to
supply the 115V necessary for the ignition circuit. For the
incoming power, a 3-wire connection is made at the rear junction
box. A new variable frequency drive replaces the standard VFD,
and the combustion blower fan has been configured to operate
at 460/3/60V (using the standard fan). Part numbers as well as
FLA and MOCP information is below.
500VA transformer: DC0500UH
VFD:
Model Range:
T234 DR-1200 to DR-1800 (1hp)
T235 DR-2000 to DR-2500(1.5hp)
T237 DR-3000 to DR-3500 (3hp)
T238 DR-4000 to DR-5000 (5hp)
Dynaforce®
Model
Voltage
Requirement
Maximum
Over Current
Protection
Full Load
Amps
[Amperes] [Amperes]
1200 -
2500
460VAC, 60Hz, 3
Phase
10
2.1
3000 -
4000
5.3
4500 -
5000
6.8
The combustion air fan motor operates on 230 VAC, 3 phase,
60 Hz on models DR1200 - 5000. Three phase voltage is
generated by the VFD and supplied directly to the fan motor on
models 1200 - 5000. Refer to Table 10 for appropriate supply
voltage to the appliance. The appliance, when installed, must be
electrically grounded in accordance with the requirements of the
authority having jurisdiction or in the absence of such
requirements, with the latest edition of the National Electrical
Code ANSI/NFPA No. 70. When the unit is installed in Canada,
it must conform to the Canadian Electrical Code, C22.1, Part 1
and/or local Electrical Codes.
• All wiring between the appliance and field installed devices
shall be made with wire having minimum 220ºF (105ºC)
rating.
• Line voltage wire external to the appliance must be
enclosed in approved conduit or approved metal clad cable.
• The pump must run continuously when appliance is firing.
• To avoid serious damage, DO NOT ENERGIZE the
appliance until the system is full of water. Ensure that all air
is removed from the pump housing and piping before
beginning initial operation. Serious damage may result if the
appliance is operated without proper flow.
•
Provide the appliance with proper overload protection.
5.2 VARIABLE FREQUENCY DRIVE (DR1200 –
5000)
This appliance uses a VFD which provides power to the
combustion fan. The fan motor operates on 230VAC 3 phase
power. This three phase voltage is generated by the VFD and
supplied directly to the fan motor. The VFD receives a 4-20mA
modulating signal from the SOLA to vary the frequency of the
voltage supplied to the fan motor from 20 Hz up to 60 Hz. This
varies the output of the combustion air fan from 20% up to 100%
of capacity corresponding to the same variation in burner input.
Once the self-checks are completed by the SOLA, the VFD is
provided with a signal to operate at soft start level for initial
burner ignition. After main burner ignition is established, the
modulating signal is generated by the VFD to vary fan speed
based on desired water temperature set point.
CAUTION
The voltage output from the variable frequency drive to the
combustion air fan is 230VAC, 3 Phase. AVOID contact with
high voltage wiring
5.3 DIFFRENTIAL AIR PRESSURE SWITCH
Models 300 to 1000 use a fan speed sensing line in the PWM
control to prove air flow. A normally open differential air pressure
switch is used to prove operation of the combustion air fan on
the DR1200 – 5000. The pressure switch sensing points are
installed at the fan outlet where air moves into the inlet of the
burner. One point measures total pressure (+air) and is
connected to a pitot tube facing the flow from the fan paddle
wheel. The other point measures static pressure. Differential
pressure at the switch will be affected by blockages at the fan