tekmar 512 Installation

- Data Brochure

D 512

Programmable Thermostat 512

09/09

Table of Contents

Display / Keypad Operation ............ pg 1

Display Symbols ............................. pg 2

General ........................................ pg 2-3

Sequence of Operation................pg 4-6

Type 512 (Two Stage Heating) ... pg 4

Type 512 (Heat / Cool) ............pg 5-6

Menus ........................................ pg 6-10

View Menu ................................ pg 6

Adjust Menu ........................pg 7-10

Error Messages ......................pg 11

Installation .................................pg 12-13

Wiring the 512 ...........................pg 14-17

Warranty ....................................... pg 20

Display / Keypad Operation

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.

Displays the

current

Displays an abbreviated

name of the selected item

Displays the current value

Displays the current

status of the

thermostat's inputs,

outputs and operation

Selects Menus, Items

and adjusts settings

of the selected item

Display Symbols

Warning

Displays when an error exists.

Heat One

Displays when the heat one contact is on.

Access Level

Displays when in the user access level.

Early Start

Displays when the thermostat is in early start.

Heat Two

Displays when the heat two contact is on.

Cool One

Displays when the cool one contact is on.

General

CYCLES PER HOUR (HEAT CYCLE and COOL CYCLE)

The thermostat operation is based on cycles per hour. The number of cycles per hour is adjustable through the HEAT CYCLE and COOL CYCLE settings in the Adjust menu. During each cycle that heating or cooling is required, the thermostat turns on the Heat or Cool relay(s) 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 or cooling, the appropriate on time is increased. If the zone requires less heat or cooling, the appropriate on time is reduced.

In order to prevent short cycling of the heating relay(s), the thermostat ensures that the relay(s) remains on or off for a minimum amount of time. In order to prevent short cycling of the Cool relay, the minimum cooling on time and minimum cooling off time settings are adjusted in the Adjust menu of the 512.

An Auto Cycle setting is available for both the heating cycle and the cooling cycle. This setting allows the thermostat to determine the best number of cycles per hour that balances both temperature swings and equipment cycles.

Cycles Per Hour

on onon

offoff

⇐ Cycle Length ⇒

Time

off

EARLY START (

)

Heating - The early start function for heating ensures that the zone is up to the proper

70°F (21°C)

62°F (17°C)

Early Start OFF

temperature at the beginning of each period. The thermostat learns the recovery rate over multiple setback events in order to determine the proper lead time for the zone. If both an air sensor and a slab sensor are used, the lead time is the greater of the air sensor’s or

70°F (21°C)

62°F (17°C)

Early Start ON

UnOccupied

Occupied

the slab sensor’s requirements. Cooling - The early start function, when used with cooling, allows the cooling system to turn on 30 minutes prior to the beginning of a period that requires cooling.

NOTE: The Early Start feature occurs when the schedule changes from a low temperature to a higher temperature.

AUXILIARY SENSORS

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 up to two separate sensors. These sensors can be either indoor sensors, slab sensors, a remote 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 times for the relay(s) in the thermostat. Either one or both of the auxiliary sensor inputs can be configured for indoor sensors. This setting is made through the Adjust menu of the thermostat. If more than one sensor, either the built-in sensor or an auxiliary sensor set as an indoor sensor, is being used to measure the zone temperature, the temperature of the active sensors is averaged and used to calculate the on time of the relay(s).

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. If more than one slab sensor is used, the slab temperatures are averaged by the thermostat.

Remote Sensor

A single remote sensor can be connected to the thermostat. The temperature measured by a remote sensor does not affect the on time of the relays and is only used for display purposes.

Outdoor Sensor

A single outdoor sensor can be connected to the thermostat. The temperature measured by an outdoor sensor does not affect the on time of the relays and is only used for display purposes.

ACCESS LEVELS

The tekmar Programmable Thermostat has two access levels. These access levels restrict the number of items available in the menus of the

Made in Canada

Meets Class B:

Canadian ICES

thermostat. The two access levels are User and Installer. This selection is made using the DIP switch located on the circuit board inside the

FCC Part 15

938-

512

thermostat.

Switch Settings:

e/Heat-Cool

Installer/User

2 Stag

60 Hz 3 VA

V (ac) 2

Power: 24 V ± 10%

Relay:

Class 2

The 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.

The User access level allows the end user to adjust the time, temperatures and schedules used by the thermostat.

Dip Switch

TWO STAGE HEAT

The two stage mode of operation is selected using the DIP switch located on the circuit board inside the thermostat.

In cases where a one stage heating system can not provide sufficient heat under all conditions, a second stage of heat can be added to supplement the first stage. A two stage system therefore has one thermostat controlling two output relays.

Two Stage Logic

The temperature in a two stage zone is controlled by varying the on time of the Heat 1 and Heat 2 relays during a cycle. Under light loads, the Heat 1 relay is cycled on and off. As the load increases, the Heat 1 relay on time is increased until it reaches the maximum of the cycle length or, if a slab sensor is used, the slab temperature reaches the slab maximum setting. The Heat 2 relay is then cycled and its on time is increased as the load increases. When the heating load decreases, the on time of the Heat 2 relay is reduced until the Heat 2 relay is turned off completely. The thermostat then reduces the on time of the Heat 1 relay

NOTE: When using a slab sensor, the Heat 2 relay may be on while the Heat 1 relay is off if the slab temperature has reached the slab maximum setting.

Air Sensor(s) Only Operation

When operating with only an air sensor, the on times for the Heat 1 and Heat 2 relays are calculated to satisfy the requirements of the air sensor.

Slab Sensor Only Operation

When operating with only a slab sensor, the on times for the Heat 1 and Heat 2 relays are 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 1 relay to satisfy the slab sensor’s requirements and on times for the Heat 1 and Heat 2 relays to satisfy the air sensor’s requirements. The thermostat operates the Heat 1 relay for the longer of these two on times.

While the minimum slab temperature is satisfied, the on times of the Heat 1 and Heat 2 relays are calculated to satisfy the air temperature requirements

During heavy loads, the maximum slab temperature setting limits the on time of the Heat 1 relay. In this situation, the Heat 2 relay may be on while the Heat 1 relay is off.

NOTE: During light heating loads, overheating can occur due to the minimum slab temperature requirements

Mode

Heat In the heat mode, the Heat 1 and Heat 2 relays are operated to satisfy the

temperature requirement of the zone

Off In the Off mode, the Heat 1 and Heat 2 relays are not operated.

NOTE: If an air or slab sensor is active in the Off mode, a freeze protection is enabled

that allows the relays to be operated to keep the zone above 35°F (2°C).

HEAT / COOL

The Heat / Cool mode of operation is selected using the DIP switch located on the circuit board inside the thermostat

Air Sensor(s) Only Operation

When operating with only an air sensor, the on times of the Heat 1 relay and the Cool relay are calculated to satisfy the requirements of the air sensor

Slab Sensor Only Operation

When operating with only a slab sensor, the on time of the Heat 1 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: When operating with only a slab sensor, the Cool relay does not operate. 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 1 relay to satisfy the slab sensor’s requirements and an on time to satisfy the air sensor’s requirements. The Heat 1 relay operates for the longer of these two on times. The thermostat also calculates an on time for the Cool relay to satisfy the air sensor’s requirements. In this situation, heating and cooling can happen at the same time to prevent the space from overheating. This is most likely to occur when the slab is operating at the slab minimum temperature

While the minimum slab temperature is satisfied, the Heat 1 relay on time is calculated to satisfy the air temperature setting. However, the maximum slab temperature setting limits the Heat 1 relay on time when the slab temperature becomes too warm. In this situation, underheating can occur in the space.

Mode

Auto In the Auto mode, the thermostat automatically switches between heating and

cooling the space. However, the heating operation has priority over the cooling operation. In this mode, the minimum slab temperature is maintained even when the thermostat is cooling the air.

Heat In the Heat mode, the Heat 1 relay is operated to satisfy the heating

temperature requirement of the zone and cooling is disabled.

Cool In the Cool mode, the Cool relay is operated to satisfy the cooling temperature

requirement of the zone and heating is disabled. If a slab sensor is used, the slab minimum is ignored.

Off In the Off mode, the Heat 1 and Cool relays are not operated.

NOTE: If an air or slab sensor is active in the Off mode, a freeze protection is enabled that

allows the Heat 1 relay to be operated to keep the zone above 35°F (2°C).

Heating / Cooling Interlock

Time Interlock

In order to prevent frequent changes between heating and cooling, the thermostat has a Cooling Interlock setting. Once the Heat 1 relay has been off for a minimum of one heating cycle or the length of the Cooling Interlock, (whichever is longer) cooling is permitted.

Temperature Interlock

When in the Auto mode, the cooling temperature is limited to 3°F (1.5°C) above the heating temperature. If the cooling temperature is set below the heating temperature, the thermostat automatically adjusts the cooling setpoint.

When operating in the Cool mode, there is no interlock between the heating and cooling temperature.

View Menu (1 of 1)

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 2 must be set to Out.)

SLAB

The current slab temperature.

(Must have an active slab sensor. If two slab sensors are present, this is the average temperature.)

The MIN segment is displayed when running on Min.

REMOTE

The current temperature at the remote sensor.

(Sens 1 must be set to Rem.)

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