- Data Brochure
D 650
Snow Melting Control 650
08/10
The tekmar Snow Melting Control 650 is a microprocessor-based control that uses a Slab Sensor 072 and an
Outdoor Sensor 070 (both supplied with the control) to maintain a snow melt slab at a set surface temperature
during snow melting. When melting is not required, the melting system is either shut down or the slab is
maintained at an idling temperature for faster response and improved safety. The melting mode is initiated
manually by a button on the control or by an optional remote switch. Built in energy saving features include warm
and cold weather cut offs that automatically shut the melting system down in warm weather or extremely cold
conditions. The timer included in the control can be programmed to operate the snow melt system for a set time
Outdoor
Slab Sensor
Target Slab
Item
On
Time
Start Stop
Snow Melting
Control 650
Pulse Width Modulation
F
CWCO
Idling
Melting
period. Viewing and programming the operating parameters in either °C or °F is accomplished through a digital
LCD. The display indicates an error message whenever a sensor or its wiring develops a fault.
Sequence of Operation
Powering up the Control
After the Snow Melting Control 650 is powered-up, the LCD
screen segments are turned on for 3 seconds. The control
then monitors and displays the outdoor temperature.
Melting Mode
The Snow Melting Control 650 is a manual control; in order to
start the melting system with the control powered up, the
Programming
mode
indicator
“Start” button is pushed. The melt system can also be started
by setting the “Melt at power up” DIP switch to “On” and
powering up the control. When the control is in melting mode,
the melting pointer flashes slowly and the system relay is
turned on. The heat relay is cycled on and off to maintain the
slab at the “Melting” temperature. The method used to cycle
the heat relay is called Pulse Width Modulation (PWM). For
more information on PWM, see Essay 000. Once the slab has
Item
identifiers
reached the “Melting” temperature, a timer starts. The control
remains in melting mode until the timer “On Time” reaches
zero, the “Stop” button is pushed, or the remote switch is
turned off.
Note: If the remote switch is turned off and on again to restart
the system, the switch must be kept off for at least 1
Item
selection
and display
button
second for the control to fully power down.
Idling Mode
When the snow melting system starts from a cold temperature,
the time required for the slab to reach “Melting” temperature
can be excessive. To decrease this start up time, the slab can
Wiring
Chamber
and
Terminals
be maintained at an “Idling” temperature. The Idle feature is
also useful for preventing frost and light ice formation. When
the control is in idling mode, the idling pointer flashes slowly
and the system relay is turned on. The heat relay is cycled on
and off to maintain the slab at the “Idling” temperature.
Warm Weather Cut Off (WWCO)
If the control is in melting or idling mode and the “Slab” and “Outdoor” temperatures rise above the “Melting” temperature, the control
shuts down the melting system and enters Warm Weather Cut Off mode. During WWCO, the WWCO pointer flashes slowly. The
timer continues to run and normal operation is resumed when the “Outdoor” temperature drops below the “Melting” temperature.
Cold Weather Cut Off (CWCO)
Maintaining the slab at a “Melting” or “Idling” temperature in extremely cold conditions can be expensive and may even be
impossible. When it does snow at these colder temperatures, the snow is usually dry, light and less slippery. The control therefore
turns the melting system off when the “Outdoor” temperature drops below the “CWCO” setting. While the control is in CWCO, the
CWCO pointer flashes slowly. The timer continues to run until the slab temperature drops below the “Target Slab” temperature.
When the outdoor temperature rises above the “CWCO” temperature, the control exits CWCO and continues with normal operation.
On Time
The control has a built in timer which is used to set the length of time the control operates the system in melting mode. The timer begins
counting down when the snow melt system is turned on and the slab has reached the “Melting” temperature.
Hole for mounting screw
Meets Class B:
Canadian ICES
FCC Part 15
Made in Canada
tektra 906-09
PRGM
Outdoor
Slab Sensor
Target Slab
Item
Snow Melting Control 650
Pulse Width Modulation
Melt at power up
34
21
On
Power
Off
C-
R+
Heat
Signal wiring
must be rated
at least 300V
Hole for mounting screw
Power: 24 V (ac) ± 10% 50/60 Hz 3 VA
24 V (dc) ± 10% 0.03A
Relays: 240 V (ac) 10 A 1/3hp
H1113E
FC
Time
On
CWCO
Idling
Melting
Start Stop
No power
8
7
5
6
Com
Slab
Sen
Sen
System
Out
Sen
9
Date Code
Temperatures
and On Time
display
°C or °F
indicators
Programming
and Melt
Start/Stop
buttons
1 of 4 © 2010 D 650 - 08/10
Installation
Caution
Improper installation and operation of this control could result in damage to the equipment and possibly even
personal injury. It is your responsibility to ensure that this control is safely installed according to all applicable codes
and standards. This electronic control is not intended for use as a primary limit control. Other controls that are
intended and certified as safety limits must be placed into the control circuit.
Step One Getting ready
Check the contents of this package. If any of the contents listed are missing or damaged, please refer to the Limited Warranty
and Product Return Procedure on the back of this brochure and contact your wholesaler or tekmar sales agent for assistance.
Type 650 includes:
Data Brochures:
Other information available:
ote: Carefully read the Sequence of Operation section in this brochure to ensure that you have chosen the proper control and
N
• One Snow Melting Control 650 • One Slab Sensor 072 • One Outdoor Sensor 070
• Data Brochures D 001, D 070, D 072, D 650 • Application Brochures A 650
• Essay E 001, Essay E 005.
understand its functions within the operational requirements of your system.
Step Two Mounting
The control is mounted in accordance with the instructions in the Data Brochure D 001.
Step Three Rough-in wiring
All electrical wiring terminates in the two wiring chambers at the bottom front of the control. If the control is to be mounted on
an electrical box, the wiring can be roughed-in at the electrical box prior to installation of the control (see Brochure D 001).
Standard 18 AWG solid wire is recommended for all low voltage wiring to this control.
Power should not be applied to any of the wires during the rough-in wiring stage.
• Install the Outdoor Sensor 070 according to the instructions in Data Brochure D 070 and run the wiring back to the control.
Do not connect the wires to the terminals yet.
• Install the Slab Sensor 072 in the slab halfway between the heating pipes or electric
cables and within 1 inch of the slab surface (see adjacent diagram). The sensor
should be placed approximately 3 feet (1m) from the edge of the slab. Run the wiring
back to the control but do not connect the wires to the terminals yet.
• Install a 24 V (ac) Class 2 transformer with a minimum 5VA rating and run the wiring
from the transformer to the control.
A Class 2 transformer must be used
. Do not
connect either of the transformer secondary wires to ground.
• Or provide a 24V DC power source and run wiring to the control location.
• Run wiring from the heating device and system circuits to the control.
1" (25mm)
Slab Sensor
SLAB
halfway between the
pipes or electric cables
Step Four
Testing and connecting the wiring
Caution
These tests are to be performed using standard testing practices and procedures and should only be carried out by properly
trained and experienced persons. A good quality electrical test meter, capable of reading from at least 0 — 200 Volts, and
at least 0 — 2,000,000 Ohms, is essential to properly test this control. At no time should voltages in excess of 28 V be
measured at any of the wires connected to the control.
Test the sensors
• This test must be performed
power is applied to the control and
before
the sensors are connected to the terminal strip.
before
Test the sensors according to the instructions printed in the enclosed Data Brochure D 072.
Test the power supply
• Ensure exposed wires are not grounded or in contact with other wires. Turn on the 24 V ac power supply and, using a
voltmeter, you should measure between 20 and 28 volts between the power and common terminals.
• Turn off the power and complete the electrical connections to the terminal strip of the control.
Power and output connections
The installer should test to confirm that no voltage is present at any of the wires.
• Connect the power supply to terminals
Power C — R
• Connect the heating device circuit to terminals
• Connect the system circuit to terminals
System
(1 and 2).
(3 and 4).
Heat
(5 and 6).
Sensor connections — Caution, voltage is never applied to these terminals
• Connect the Slab Sensor 072 to terminals
• Connect the Outdoor Sensor 070 to terminals
© 2010 D 650 - 08/10 2 of 4
Com Sen and Slab Sen
Com Sen and Out Sen
(7 and 8).
(7 and 9).
24 V Only
1C-2R+34
Power
power
supply
24 V
10A
Heat
Heat Relay
closes to turn on
heating device
5
System
System Relay
closes when in
melting or idling
10A
modes
6
Com
Sen
Do not apply
power here
89
7
Out
Slab
Sen
Sen
Slab
Sensor
Outdoor
072
Sensor
070