028-5011
LIT-R820_REV2-E03
5
24 Vac Power& Wiring
•
It is not necessary to ground any leg of the transformer to earth with the controller card.
•
The controller uses internally a half wave rectifier bridge. On 0 to 10 Vdc control signal, the reference of the control
signal is the Common of the power supply of the SCR controller card.
•
Use a Class 1 ( properly fused ) or Class 2, CSA or UL recognized transformer.
High voltage Wiring
General cautions:
•
High voltages are present on the terminals of these devices. Please read all the instruction in this manual carefully.
•
The 45 & 75 Amps models need to be wired with the supplied high voltage lugs.
Attach the wire to the lug first
,
and then screw the lug to the power module.
•
Have the wiring done by a qualified and skilled professional.
•
High voltage and amperage can be fatal.
•
All wiring must conform to national electrical code regulations.
•
The instrument must be wired before applying power.
•
Protect circuits with semi conductor fuses.
•
For in panel installation, derating amperage curves are available from the factory.
Specifications
Operating Conditions: 0°C to 80°C ( 32°F to 176°F ) / 0 % to 95 % R.H. non-condensing
See power derating curves document
Thermostatic protection: Self-resetting. Auto shut off when SCR ambient temp. is above 82°C ( 180°F )
Power supply: 24 Vac -15%, +10% 50/60 Hz; 2 VA
Use a Class 1 ( properly fused ) or Class 2, CSA or UL recognized transformer.
Troubleshooting
Check
1
Check general wiring, as per heater manufacturer diagram
Be sure you understand the system and its normal operation
2
Verify high voltage power supply wiring
Verify that correct voltage is present at the heater with proper wire size
3
Verify low voltage 24 Vac power supply wiring
24 Vac is present at terminals 1 & 2 of the R820 SCR
4
Create or simulate 100 % heating demand
Using present control system
R820 Configured for 0 to 10 Vdc input signal
•
Signal between terminals 1 & 3 is 10 Vdc or superior
•
Dip switch properly configured: S1=Off, S2=Off, S3=Off & S4=On
•
Be sure that the polarity is correct and not re to +, - to -
•
Red status LED on SCR is on 100 % of the time
R820 Configured for 4 to 20 mA input signal
•
Signal between terminals 1 & 3 is 20 mA or superior
•
Dip switch properly configured: S1=Off, S2=Off, S3=On & S4=Off
•
Be sure that the polarity is correct and not re to +, - to -
•
Red status LED on SCR is on 100 % of the time
R820 Configured for 0 to 135
Ω
input signal
•
Signal between terminals 1 & 3 is 135
Ω
or superior
•
Dip switch properly configured: S1=On, S2=On, S3=Off & S4=Off
•
Red status LED on SCR is on 100 % of the time
5
Verify amperage consumption of the heater
Red status LED on SCR is on 100 % of the time
6
Verify & correct 24 Vac power supply to the SCR
Verify low voltage fuses, protections, flow switch, etc………
7
Verify control wiring & control signal
Correct control signal is present at the SCR
Check polarity of control signal
8
Verify fuses & all protections & contact the heater manufacturer
Viconics Electronics Inc.
9245, Langelier Blvd, St-Leonard, Quebec, Canada H1P 3K9
www.viconics.com
Important Notice:
These instruments have
undergone rigorous tests
and verifications prior to
shipment to ensure
proper and reliable
operation in the field.
However, like other such
products, they are
subject to failure. It is
therefore the
responsibility of the
installer / user / electrical
panel designer to
incorporate safety
features
and
devices
( such as relays, flow
switch, thermal
protections, etc.. ) to
protect the entire system
from catastrophic failure.
