Tekmar D 508 User manual

1 of 12 © 2010 D 508 - 05/10
- Data Brochure
Thermostat 508
D 508
05/10
Table of Contents
Display / Keypad Operation............ pg 1
Display Symbols ............................. pg 2
General ........................................ pg 2-3
Sequence of Operation................pg 3-4
Installation....................................pg 4-5
Wiring Examples.......................... pg 6-7
User Interface ................................. pg 8
Menus ........................................ pg 8-10
View Menu................................ pg 8
Adjust Menu ............................ pg 9
Schedule Menu ...................... pg 10
Error Messages ........................... pg 10
Warranty ....................................... pg 12
The thermostat’s display has four distinct fields. These fields are the Menu field, the Item
field, the Number field and the Status field. The four buttons on the face of the thermostat are
used to navigate through the menus and items to view and / or adjust the desired settings.
Display / Keypad Operation
Displays the
current
menu
Displays an abbreviated
name of the selected item
Displays the current value
of the selected item
Selects Menus, Items
and adjusts settings
Displays the current
status of the
thermostat's inputs,
outputs and operation
AWAY

© 2010 D 508 - 05/10 2 of 12
CYCLES PER HOUR
The thermostat operation is based on cycles per hour. The number of cycles per hour is adjustable
through the HEAT CYC setting in the Adjust menu. During each cycle that heating is required,
the thermostat turns on the Heat relay for a calculated amount of time. This amount of time is
the “ON time”. The ON time is calculated based on the requirements of the zone. If the zone
requires more heating, the ON time is increased. If the zone requires less heating, the ON time
is reduced.
General
Display Symbols
Warning
Displays when an error exists.
Access Level
Displays when in the user
access level.
Heat One
D i s p l a y s w h e n t h e h e a t c o n t a c t
is on.
In order to prevent short cycling of the heating relay, the
thermostat ensures that the relay remains on or off for
a minimum amount of time.
An AUTO CYC setting is available for the heating cycle.
This setting allows the thermostat to determine the
best number of cycles per hour that balances both
temperature swings and equipment cycles.
AUXILIARY SENSOR
The thermostat has a single built-in sensor to measure air temperature at the
thermostat. In addition to the built-in sensor, the thermostat has terminals to connect
one auxiliary sensor. This sensor can be either an indoor sensor, a slab sensor, or
an outdoor sensor.
Indoor Sensor
An indoor sensor is used to measure the air temperature in the zone that the thermostat
is controlling. The temperature being read by the indoor sensor is used in the calculations
of the ON time for the relay in the thermostat. This setting is made through the Adjust
menu of the thermostat. If the built-in sensor is set to ON and the auxiliary sensor is set
to Indoor, the temperatures of the sensors are averaged and used to calculate the ON
time of the relay.
Slab Sensor
A slab sensor is used to measure the slab temperature in the zone that the thermostat
is controlling. The temperature being read by the slab sensor is used in the calculations
of the ON time for the Heat relay and allows the thermostat to operate the slab between
the slab minimum and slab maximum settings.
⇐Cycle Length ⇒
Time
offoff off
on onon
Cycles Per Hour

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Outdoor Sensor
An outdoor sensor can be connected to the thermostat. The temperature measured by
an outdoor sensor does not affect the ON time of the relay and is only used for display
purposes.
ACCESS LEVELS
Sequence of Operation
AIR SENSOR(S) ONLY OPERATION
When operating with only an air sensor, the ON time for the Heat relay is calculated to
satisfy the requirements of the air sensor.
SLAB SENSOR ONLY OPERATION
When operating with only a slab sensor, the ON time for the Heat relay is calculated to
satisfy the requirements of the slab sensor. The thermostat operates to maintain the slab
at the minimum slab temperature setting.
NOTE: Operating with only a slab sensor can lead to either overheating or underheating
of the space.
AIR AND SLAB SENSOR OPERATION
When operating with both air and slab sensors, the thermostat calculates an ON time for the
Heat relay to satisfy the slab sensor’s requirements and an ON time to satisfy the air sensor’s
requirements. The Heat relay operates for the longer of these two ON times.
During light heating loads, overheating can occur due to the minimum slab temperature
requirements.
During heavy heating loads, the maximum slab temperature setting limits the ON time of
the Heat relay. In this situation, underheating can occur.
The 508 thermostat has two access levels.
These access levels restrict the number of items
available in the menus of the thermostat. The
two access levels are User and Installer. This
selection is made using the DIP switch located
on the circuit board inside the thermostat.
Installer access level - allows the installer
to adjust all of the settings in the thermostat
including those required to match the thermostat
to the mechanical system and the devices
used.
User access level - allows the end user
to adjust the temperatures used by the
thermostat.
NO
POWER
2
Sensor
1
24 V ±10% 50/60 Hz 1.5 VA.
24 V (ac) 2 A Class 2
Installer
Access level
Not used
Power:
Relay:
For 3 wires,
install jumper
R to Rh
944-02
Thermostat 508
One Stage Heat
508
4653
RhRCW
User
Meets Class B:
Canadian ICES
FCC Part 15
Made in
Canada
Apr 2010
Lot 1234
12
ON
24 V
Dip Switch
Set to User access level once installation and settings have been completed.
Note: DIP switch 2 is not used.

© 2010 D 508 - 05/10 4 of 12
Installation
STEP ONE GETTING READY
Check the contents of this package. If any of the contents are missing or damaged, please
contact your wholesaler or tekmar sales representative for assistance.
Type 508 Includes:
•
• One Thermostat 508
•
Data Brochure D 508
•
• User Brochure U 508
STEP TWO REMOVING THE FRONT COVER
Place a screwdriver or similar object into the small slot located in the top of the thermostat.
Push the screwdriver against the plastic tab and pull the top of the front cover so that it pivots
around the bottom edge of the base.
Menu
Item
Remove cover
Push tab
1
2
MODE
Heat In the heat mode, the Heat relay is operated to satisfy the temperature
requirement of the zone.
Off In the OFF mode, the Heat relay is not operated.
NOTE: If an air or slab sensor is active in the OFF mode, a freeze protection is enabled
that allows the Heat relay to be operated to keep the zone above 35°F (2°C).
STEP THREE MOUNTING THE BASE
The thermostat should be installed on an interior wall of the desired zone approximately 5’ (1.5
m) above the floor. Do not mount the thermostat in a location that may be affected by localized
heat sources or cold drafts. It may be necessary to install a draft barrier behind the thermostat to
prevent air from blowing through the wiring hole and affecting the thermostat’s built-in sensor.
Mount the base directly to the wall using two #6
1” screws. The screws are inserted through the
mounting holes and must be securely fastened
to the wall. If possible, at least one of the screws
should enter a wall stud or similar surface.
If the thermostat is to be mounted to a 2” x
4” electrical box, order an Adaptor Plate 007.
This plate mounts to the electrical box and the
thermostat mounts to the plate. Ensure that the
electrical box does not provide cold air to the
thermostat. #6 1” screws

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STEP FOUR ROUGH IN WIRING
•
18 AWG or similar wire is recommended for all 24 V (ac) wiring.
•
All wires are to be stripped to 1/4” (6 mm) to ensure proper connection to the control.
•
Run wires from the 24 V (ac) power to the thermostat. Use a clean power source to
•
If an auxiliary sensor is used, install the sensor according to the appropriate Data
Brochure and run two wires from the sensor to the thermostat.
•
Run wires from the heating device to the thermostat.
STEP FIVE WIRING THE THERMOSTAT
(Refer to the examples on the following page.)
24 V (ac) Power
Connect the 24 V (ac) power to the R and C terminals of the thermostat. This connection
provides power to the microprocessor and display of the thermostat.
Auxiliary Sensor
Either an indoor, slab, or outdoor sensor may be connected to the auxiliary sensor input.
Connect the two wires from the auxiliary sensor to the Sensor terminals.
Heat Relay (Rh – W)
The Heat Relay Rh – W terminals are an isolated output. There is no power available
on these terminals from the thermostat. These terminals are to be used as a switch for
a 24 V (ac) circuit. This circuit can operate a low current 24 V (ac) device directly or an
external relay to enable a line voltage or high current device.
STEP SIX INSTALLING THE FRONT COVER
Align the hinges on the bottom of the front cover with the bottom of the thermostat mounting
base. Pivot the front cover around the bottom hinges and push the top against the mounting
base until it snaps firmly in place.
Pivot front
cover around
bottom hinges
Align hinges
on bottom
of front cover
1
2
Menu
Item
NOTE: If the 508 is to be used for remote sensing (i.e. The built-in air sensor is disabled
and an indoor sensor is being used.) Mount the thermostat in the desired location in an
appropriate manner.

© 2010 D 508 - 05/10 6 of 12
Wiring Examples
NO
POWER
2
Sensor
1
24 V ±10% 50/60 Hz 1.5 VA.
24 V (ac) 2 A Class 2
Installer
Access level
Not used
Power:
Relay:
For 3 wires,
install jumper
R to Rh
944-02
Thermostat 508
One Stage Heat
508
4653
RhRCW
User
Meets Class B:
Canadian ICES
FCC Part 15
Made in
Canada
Apr 2010
Lot 1234
12
ON
24 V
N115 V (ac)
24 V (ac)
Class 2
Transformer
L
Power
Zone 1
Zone2
Zone 3
Zone4
End Switch
C
Zone 2
WtN4 RC
Zone 3
WtN4 RC
Zone 4
WtN4 R
tN4 Wiring Center 316
Four Zone Pumps
WtN4CtN4C
Zone 1 Expansion End Switch
C
Input Power
RR
H8002A
X X
Input Power: 24 V (ac) ±10% 60 Hz
11 VA Class 2
End Switch: 24 V (ac) 2 A
Pump Relays: 115 V (ac) 5 A
Zone Power: 115 V (ac) 12 A
Made in Canada
tektra 1031-01
Use at least 167°F (75°C) conductors
Black
Red
Auxiliary Sensor
Zone
Valve NO
POWER
2
Sensor
1
24 V ±10% 50/60 Hz 1.5 VA.
24 V (ac) 2 A Class 2
Installer
Access level
Not used
Power:
Relay:
For 3 wires,
install jumper
R to Rh
944-02
Thermostat 508
One Stage Heat
508
4653
RhRCW
User
Meets Class B:
Canadian ICES
FCC Part 15
Made in
Canada
Apr 2010
Lot 1234
12
ON
24 V
N
L
Auxiliary Sensor
115 V (ac) 24 V (ac)
Class 2
Transformer
M
Wiring to 24 V (ac) Zone Valve
Wiring to a tekmar Wiring Center 315 or 316
115 V (ac)
24 V (ac)
Sensor Wires
115 V (ac)
24 V (ac)
Sensor Wires

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Wiring to Unpowered 24 V (ac) Relay
2
1
8
7
3
4
5
6
Zone Pump
NO
POWER
2
Sensor
1
24 V ±10% 50/60 Hz 1.5 VA.
24 V (ac) 2 A Class 2
Installer
Access level
Not used
Power:
Relay:
For 3 wires,
install jumper
R to Rh
944-02
Thermostat 508
One Stage Heat
508
4653
RhRCW
User
Meets Class B:
Canadian ICES
FCC Part 15
Made in
Canada
Apr 2010
Lot 1234
12
ON
24 V
N
L
Auxiliary Sensor
24 V (ac)
Class 2
Transformer
115 V (ac)
Unpowered
Relay
Wiring to Switching Relay
Auxiliary Sensor
Zone Pump
L
N
115 V (ac)
W
(T)(T)
R
NO
POWER
2
Sensor
1
24 V ±10% 50/60 Hz 1.5 VA.
24 V (ac) 2 A Class 2
Installer
Access level
Not used
Power:
Relay:
For 3 wires,
install jumper
R to Rh
944-02
Thermostat 508
One Stage Heat
508
4653
RhRCW
User
Meets Class B:
Canadian ICES
FCC Part 15
Made in
Canada
Apr 2010
Lot 1234
12
ON
24 V
24 V
W
(T)(T)
R
HNXX HNHN NH
Com Switching Relay
Zone 1 Zone 2 Zone 3
Class 2
Transformer
W
(T)(T)
R
115 V (ac)
24 V (ac)
Sensor Wires
115 V (ac)
24 V (ac)
Sensor Wires

© 2010 D 508 - 05/10 8 of 12
View Menu
ROOM TARGET
The current desired air temperature for the space. This item is
only available in the Installer access level.(Must have an active
air sensor.)
ROOM
The current air temperature for the space. (Must have at least one
active air sensor. This is the average of all active air sensors.
OUTDOOR
The current temperature at the outdoor sensor.
(SENS must be set to OUT.)
SLAB
The current slab temperature. (Must have an active slab sensor.)
The MIN segment is displayed when running at Slab Minimum.
MENU BUTTON
The menus display in the Menu Field at the left of the LCD.
Three menus are available:
• View
• Adjust
• Schd (Schedule)
To select a menu, press and release the Menu button.
ITEM BUTTON
In each menu, a group of items can be selected. The abbreviated name of the selected
item displays in the Item field of the LCD display.
• To view the next available item, press and release the Item button.
• To view the previous item, hold down the Item button and press and release the Up
button.
ADJUSTING A SETTING
To adjust a setting:
1. Use the Menu button to select the appropriate menu.
2. Use the Item button to find the desired setting.
3. Use the Up or Down button to adjust the setting.
User Interface

9 of 12 © 2010 D 508 - 05/10
Adjust Menu
MODE
Current mode of operation of the thermostat.
OFF, HEAT
ROOM HEAT
Desired temperature for heating. (Must have an active air sensor
and be set to HEAT.)
35 to 100°F (1.5 to 38.0°C)
SLAB MINIMUM
Minimum slab temperature. (Must have an active slab sensor.)
OFF, 34 to 122°F (OFF, 1.0 to 50.0°C)
SLAB MAXIMUM
Maximum slab temperature. This item is only available in the
Installer access level. (Must have an active slab sensor.)
34 to 122°F, OFF (1.0 to 50.0°C, OFF)
SENSOR
Selects the type of auxiliary sensor present. This item is only
available in the Installer access level.
OFF, Indr, SLAB, OUT
ROOM SENSOR
Selects whether the built-in sensor is functional or not. This item
is only available in the Installer access level.
OFF, On
HEATING CYCLE
Determines the number of cycles per hour for the heating equipment.
This item is only available in the Installer access level.
Au, 2 to 12
UNITS
The units of temperature used to display the items.
°F, °C

© 2010 D 508 - 05/10 10 of 12
Error Messages
E01
The thermostat was unable to read a piece of information stored
in its memory. The thermostat was required to load the factory
settings. The thermostat will stop operation until all settings are
checked. To clear this error, select the Installer access level and
check all of the settings in the Adjust menu.
E02
There are no active sensors selected on the thermostat. Either the
internal sensor must be turned on or the auxiliary sensor must be
set to either INDR or SLAB. After the fault is corrected, press any
button to clear the error message.
ROOM SHORT
The thermostat’s internal air sensor is short circuit. This cannot
be repaired in the field. The thermostat should be replaced or
returned for repair.
ROOM OPEN
The thermostat’s internal air sensor is open circuit. This cannot be
repaired in the field. Either turn off the internal sensor and use an
auxiliary sensor set to INDR or replace the thermostat. After the
fault is corrected, press any button to clear the error message.
SENSOR SHORT
The auxiliary sensor is short circuit. Locate and repair the problem
as described in the appropriate sensor brochure. After the fault is
corrected, press any button to clear the error message.
SENSOR OPEN
The auxiliary sensor is open circuit. Locate and repair the problem
as described in the appropriate sensor brochure. After the fault is
corrected, press any button to clear the error message.
Schedule Menu
AWAY OVERRIDE
Selects an automatic setback temperature of 62°F (16.5°C) without
altering the normal room temperature setting (Slab minimum is
ignored). Select between None & Away.

11 of 12 © 2010 D 508 - 05/10
Notes

All specifications are subject
to change without notice 12 of 12 D 508 - 05/10.
tekmar Control Systems Ltd., Canada
tekmar Control Systems, Inc., U.S.A.
Head Office: 5100 Silver Star Road
Vernon, B.C. Canada V1B 3K4
[phone] Fax. [phone]
Web Site: www.tekmarcontrols.com
Product design, software and literature
are Copyright © 2010 by:
tekmar Control Systems Ltd. and tekmar
Control Systems, Inc.
Literature D 508, U 508
Control Microprocessor PI control; This is not a safety (limit) control.
Packaged weight 0.46 lb. (210 g), Enclosure J, white PVC plastic
Dimensions 2-7/8” H x 2-7/8” W x 13/16” D (73 x 73 x 21 mm)
Approvals CSA C US, CSA 22.2 No
24 and UL 873, meets class B: ICES & FCC Part 15.
Ambient conditions Indoor use only, -22 to 131°F (-30 to 55°C), < 90% RH non-condensing.
Power Supply 24 V (ac) ±10%, 50/60 Hz, 1.5 VA
Relay 24 V (ac) 2 A, Class 2
Sensors NTC thermistor, 10 kΩ@ 77°F (25°C ±0.2°C) ß=3892
Included None
Optional tekmar type #070, 071, 072, 073, 076, 077, 078, 079, 082, 084.
Limited Warranty The liability of tekmar under this warranty is limited. The Purchaser, by taking receipt of
any tekmar product (“Product”), acknowledges the terms of the Limited Warranty in effect at the time of
such Product sale and acknowledges that it has read and understands same.
The tekmar Limited Warranty to the Purchaser on the Products sold hereunder is a manufacturer’s pass-
through warranty which the Purchaser is authorized to pass through to its customers. Under the Limited
Warranty, each tekmar Product is warranted against defects in workmanship and materials if the Product
is installed and used in compliance with tekmar’s instructions, ordinary wear and tear excepted. The pass-
through warranty period is for a period of twenty-four (24) months from the production date if the Product is
not installed during that period, or twelve (12) months from the documented date of installation if installed
within twenty-four (24) months from the production date.
The liability of tekmar under the Limited Warranty shall be limited to, at tekmar’s sole discretion: the cost of parts
and labor provided by tekmar to repair defects in materials and / or workmanship of the defective product; or to
the exchange of the defective product for a warranty replacement product; or to the granting of credit limited to the
original cost of the defective product, and such repair, exchange or credit shall be the sole remedy available from
tekmar, and, without limiting the foregoing in any way, tekmar is not responsible, in contract, tort or strict product
liability, for any other losses, costs, expenses, inconveniences, or damages, whether direct, indirect, special, sec-
ondary, incidental or consequential, arising from ownership or use of the product, or from defects in workmanship
or materials, including any liability for fundamental breach of contract.
The pass-through Limited Warranty applies only to those defective Products returned to tekmar during the war-
ranty period. This Limited Warranty does not cover the cost of the parts or labor to remove or transport the defec-
tive Product, or to reinstall the repaired or replacement Product, all such costs and expenses being subject to
Purchaser’s agreement and warranty with its customers.
Any representations or warranties about the Products made by Purchaser to its customers which are different from
or in excess of the tekmar Limited Warranty are the Purchaser’s sole responsibility and obligation. Purchaser shall
indemnify and hold tekmar harmless from and against any and all claims, liabilities and damages of any kind or
nature which arise out of or are related to any such representations or warranties by Purchaser to its customers.
The pass-through Limited Warranty does not apply if the returned Product has been damaged by negligence by
persons other than tekmar, accident, fire, Act of God, abuse or misuse; or has been damaged by modifications,
alterations or attachments made subsequent to purchase which have not been authorized by tekmar; or if the Prod-
uct was not installed in compliance with tekmar’s instructions and / or the local codes and ordinances; or if due to
defective installation of the Product; or if the Product was not used in compliance with tekmar’s instructions.
THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESS OR IMPLIED, WHICH THE GOVERNING
LAW ALLOWS PARTIES TO CONTRACTUALLY EXCLUDE, INCLUDING, WITHOUT LIMITATION, IMPLIED WAR-
RANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, DURABILITY OR DESCRIP-
TION OF THE PRODUCT, ITS NON-INFRINGEMENT OF ANY RELEVANT PATENTS OR TRADEMARKS, AND
ITS COMPLIANCE WITH OR NON-VIOLATION OF ANY APPLICABLE ENVIRONMENTAL, HEALTH OR SAFETY
LEGISLATION; THE TERM OF ANY OTHER WARRANTY NOT HEREBY CONTRACTUALLY EXCLUDED IS LIM-
ITED SUCH THAT IT SHALL NOT EXTEND BEYOND TWENTY-FOUR (24) MONTHS FROM THE PRODUCTION
DATE, TO THE EXTENT THAT SUCH LIMITATION IS ALLOWED BY THE GOVERNING LAW.
Product Warranty Return Procedure All Products that are believed to have defects in workmanship or materi-
als must be returned, together with a written description of the defect, to the tekmar Representative assigned to
the territory in which such Product is located. If tekmar receives an inquiry from someone other than a tekmar
Representative, including an inquiry from Purchaser (if not a tekmar Representative) or Purchaser’s customers,
regarding a potential warranty claim, tekmar’s sole obligation shall be to provide the address and other contact
information regarding the appropriate Representative.
Limited Warranty and Product Return Procedure
Technical Data
THERMOSTAT 508 One Stage Heat