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704 

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In order to properly control a hot water heating system, the amount of heat 
supplied to the building must equal the amount of heat lost by the building. 
The amount of heat delivered into a building depends on the temperature of 
the water in the heating unit and the surface area of the heating unit. Heat-
ing units with a small surface area, such as baseboard radiators, require a 
higher water temperature than heating units with a larger surface area such 
as radiant fl oors.
The amount of heat lost from a building depends on the outdoor temperature. 
As the outdoor temperature becomes colder, the amount of heat a building 
loses increases.
The operation of a hot water heating system can generally be improved by 
adjusting the supply water temperature to the system as the outdoor tem-
perature changes. Using this approach, the heat input to the building can 
be matched to the heat lost from the building. This method of controlling the 
supply water temperature to a heating system greatly improves the comfort 
of the system and is known as Outdoor Reset.

When an Outdoor Sensor is connected to the Radiant Mixing Control (RMC), the RMC provides outdoor reset. When operating in the outdoor 
reset mode of operation, the installer must set the Outdoor Design Temperature and the Design Supply Temperature in order to establish 
the relationship between the outdoor temperature and the supply water temperature. This is known as setting the Heating Curve.

SEQUENCE OF OPERATION

When the RMC receives a Demand and it is not in a WWSD, the RMC turns on the system pump and calculates a Mixing Target tem-
perature. The variable speed injection pump is then operated to maintain the Mixing Target temperature at the mixing supply sensor. 

The boiler contact operates as described in the Boiler Operation section. The RMC also provides boiler protection as described in 
the Boiler Operation section.

DEMAND

The RMC requires a demand signal before it will begin operation. The RMC can use either a powered or an unpowered demand 
signal. Once a demand signal is received, the RMC displays the demand pointer in the 
display and operates as described above.

Powered Demand

The RMC recognizes a Powered Demand Signal when 24 V (ac) is applied across the 
Com and Heat Dem terminals.

Unpowered Demand

The RMC recognizes an Unpowered Demand signal when a switch is closed between 
the Com and Heat Dem terminals.

SYSTEM PUMP OPERATION

The RMC has an internal system pump contact. This contact turns on when the RMC has a 
mixing demand and is not in a WWSD. The integrated system pump as well as an external 
boiler pump may be controlled by this relay. By providing proper fl ow in the boiler loop, the 
boiler temperature can be accurately controlled based on the mixing load.

Outdoor Reset Mode of Operation

Outdoor Reset Settings

HEATING CURVE SETTINGS

In order to establish the heating curve, the RMC must be given two points to work with. The fi rst point is the Outdoor Reset Starting 
Point and the second point is the Design Condition.

Outdoor Reset Starting Point

The Outdoor Reset Starting Point for the RMC is fi xed at 72°F (22°C). This means that when the outdoor temperature is 72°F 
(22°C), the RMC calculates a required supply water temperature (Mix Target) of 72°F (22°C).

Design Conditions

The design conditions represent the supply water temperature required to satisfy the heating system on the typical coldest day of 
the year. These are the conditions that are used when calculating the size of the heating equipment needed to heat the building. The 
Design Conditions are made up of an outdoor temperature (Outdoor Design) and a supply water temperature (Design Supply).

Com Heat

Dem

Boil Out

Powered

Demand

C

24 V (ac)

R

Switch

Com Heat

Dem

Boil Out

Unpowered

Demand

Switch

Содержание tekmar 704

Страница 1: ... Extremely versatile the Mixing Station 704 can be set up to operate as an outdoor reset control a setpoint control or a delta T limiting control General Mixing Station 704 Table of Contents TYPICAL PIPING 2 GETTING READY 3 APPLICATION 3 DESIGN PROCEDURE 3 INSTALLATION OF MIXING STATION 704 4 OUTDOOR RESET MODE 5 OUTDOOR RESET SETTINGS 5 SETPOINT AND DELTA T MODE 6 SETPOINT AND DELTA T SETTINGS 7 ...

Страница 2: ...ultiple Zone Valves Supply Sensor Boiler Sensor Outdoor Sensor M M Mixing Station 704 Mixing Station 704 Supply Sensor Boiler Sensor Outdoor Sensor Outdoor Sensor Boiler Sensor Boiler Sensor Outdoor Sensor Supply Sensor Radiant Manifold Supply Radiant Manifold Return Supply Sensor Radiant Manifold Supply Radiant Manifold Return Multiple Mixing Station 704s Multiple Temperature System Outdoor Senso...

Страница 3: ...jection circulator constant speed system circulator air elimination and the electronics to drive it all With only four piping connections needed the RMB greatly reduces the time and space required for installation The RMB can be set up to operate as an outdoor reset control a setpoint control or a delta T limiting control creating flexibility never seen before in a single unit Check the contents of...

Страница 4: ...Return bottom left hand connection as indicated on the plastic cover of the Mixing Station 704 Ensure that a proper isolation valve is installed 5 Connect the Boiler Supply and Boiler Return lines to the boiler loop using standard Primary Secondary piping practices STEP THREE FILLING 1 Fill system with tap water The system must be filled before operating the circulator The bearings are water lubric...

Страница 5: ...escribed in the Boiler Operation section The RMC also provides boiler protection as described in the Boiler Operation section DEMAND The RMC requires a demand signal before it will begin operation The RMC can use either a powered or an unpowered demand signal Once a demand signal is received the RMC displays the demand pointer in the display and operates as described above Powered Demand The RMC r...

Страница 6: ... fixed supply water temperature This type of application is a setpoint application Examples of setpoint applications include heat pump loops reheat coils and floor warming In specialized applications such as snow melting it is desirable to limit the rate of temperature increase in the system from the system s starting temperature to its operating setpoint This is desired in order to prevent thermal ...

Страница 7: ...ot been installed the RMC will Enable the boiler BOILER CONTROL When the RMC controls the boiler the RMC opens and closes the boiler contact in order to control the temperature of the boiler supply water temperature When the RMC is controlling the boiler temperature the RMC will determine the boiler supply water temperature that is required to satisfy the demands of the system The RMC will also de...

Страница 8: ...s required When a boiler sensor is connected to the control the RMC is capable of providing boiler protection When providing boiler protection the RMC limits the output of the variable speed injection pump in order to reduce the amount of cool water being returned to the boiler This allows the boiler temperature to increase to a point that avoids flue gas condensation Boiler Protection with Boiler ...

Страница 9: ...ten the cable tie as this can cause damage to the sensor The System Supply Sensor 082 is to be installed on the System Supply pipe This sensor is required at all times If a Boiler Sensor 071 is used install the boiler sensor on either the boiler supply or the boiler return Ensure that the DIP switch on the back of the circuit board of the RMC is set to ON if the sensor is installed on the boiler s...

Страница 10: ...ired using either a powered signal or an unpowered switch closure Powered Demand If a powered demand is being used connect the switched side of the 24 V ac demand circuit to the Heat Dem terminal of the terminal block Connect the second side of the 24 V ac demand circuit to the Com terminal of the terminal block Unpowered Demand If an unpowered demand is being used connect one side of the demand s...

Страница 11: ...ture is displayed when the MIX RET elements are turned on This is the current temperature at the mixing return sensor The mixing return temperature is only displayed if the Outdoor Design temperature is turned OFF and a mixing return sensor is installed Mixing Target Temperature The mixing target temperature is displayed when the MIX TARG elements are turned on This is the temperature the RMC is c...

Страница 12: ...mixing target temperature This item is only available if the outdoor design setting is not set to OFF Mixing Minimum Temperature The mixing minimum temperature is the lowest temperature that the control is allowed to use as a mixing target temperature This item is only available if the outdoor design set ting is not set to OFF Boiler Minimum Temperature The boiler minimum temperature item should b...

Страница 13: ... on the back of the RMC This is a field replaceable item Fuse rating 1 A 1 12 hp fuse T1 A 250 V ADJUSTMENT OF SETTINGS If the outdoor temperature is cold and the rooms are cold increase the MIX DSGN setting by 5 F 3 C per day TESTING THE SENSORS Do not apply voltage to the sensor or to the sensor input of the control as this will result in damage to either the sensor the control or both the sensor...

Страница 14: ...embly away from the body 4 Pull cartridge out of the motor housing 5 Install replacement cartridge making sure that the cover plate is between the cartridge flange and motor 6 Make sure the replacement cartridge corresponds to the full circulator product number A complete parts list is available from your local plumbing supply wholesaler 7 Reassemble the circulator using the new gasket and bolts su...

Страница 15: ...l Impeller Non Metallic Shaft Ceramic O Ring Gaskets EPDM ELECTRICAL DATA CHART Voltz 120 Hz 60 Ph 1 Amps 2 RPM 3250 HP 1 40 1 25 DIMENSIONS WEIGHT Ship Weight 18 5 lbs 8 4 kg Motor Type Permanent Split Capacitor Impedance Protected CONTROL ADJUSTMENT MENU Mixing Setpoint Temperature 60 to 185 F 16 to 85 C Maximum Temperature Difference Between Mixing Supply and Return 10 to 70 F 12 to 21 C Off De...

Страница 16: ... to tekmar during the warranty period This Limited Warranty does not cover the cost of the parts or labor to remove or transport the defective 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 ...

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