Taco i Series User manual
The iSeries-R is a microprocessor-based valve designed to regulate the supply water temperature to a heating system by modulating
the position of an iSeries Mixing Valve. The iSeries-R operates the valve to provide outdoor reset to the heating system. A boiler sensor
installed on the return line to the boiler is used to protect the boiler against flue gas condensation.
Outdoor Reset
In order to properly control a hot water heating system, the heat supplied to the build-
ing must equal the heat lost by the building.
• The heat supplied to the building is directly proportional to the temperature of the
water and the surface area of the heating element. The higher the temperature of the
water flowing through the heating terminal, the higher the heat output.
• The heat lost from a building is dependent on the outdoor temperature. As the out-
door temperature drops, the building heat loss increases.
These two facts lead to the concept of outdoor reset which increases the supply
water temperature as the outdoor temperature drops. Using this approach, the heat
lost from the building is matched by the heat provided by the terminal units, therefore
providing more comfort and energy savings.
Reset Ratio
The Reset Ratio sets the relationship between outdoor temperature and supply
water temperature. It determines the amount the supply water temperature is raised
for every 1 degree outdoor temperature drop. For example, if a Reset Ratio of 1.2
is selected, the supply water temperature is increased by 1.2 degrees of every 1
degree of outdoor temperature drop.
2-Way / 3-Way Mixing
An iSeries Mixing Valve may be used to mix the hot boiler water temperature with the cooler return water temperature from the system
loop. The position of the iSeries Mixing Valve is modulated in order to inject different rates of hot water into the cool system return water.
This allows for virtually any water temperature to be supplied to the heating system. When deciding between a 2-way or 3-way valve,
maximum flow rates must be considered. See the charts on page 2 before selecting style of valve / piping.
Most boilers cannot operate at low temperatures, therefore the iSeries-R can be modulated back in order to prevent the boiler from
operating at cold temperatures, by installing the boiler return sensor.
102-145
Instruction Sheet
i Series - Outdoor Reset (iSeries-R)
2-Way and 3-Way i Series Mixing Valves
SUPERSEDES: New EFFECTIVE: August 1, 2003
1
Plant ID# 001-1025
®
When using an iSeries Mixing Valve, the following piping require-
ments must be considered for proper operation.
1) In order to hydraulically isolate the boiler loop from the injection
or system loop primary/secondary piping must be used. There
must be no more than 4 pipe diameters between the tees in the
boiler loop (Note 1).
2) There must be at least 6 pipe diameters of straight pipe on either
side of the tees (Note 2) in order to prevent the momentum of water
in the boiler loop from pushing flow through the injection loop.
3) There should be a minimum of 1 foot drop on the return pipe
of the injection loop, in order to create a thermal trap (Note 3) and
prevent unwanted heat transfer.
4) When using a 2-way iSeries Mixing Valve, a balancing valve
must be located between the tees in the system loop, in order to
provide a pressure drop to induce flow through the mixing loop.
2-Way iSeries Mixing Valve Selection
In order to properly size the 2-Way iSeries Mixing Valve, follow the design procedure below:
1) Determine the design radiant heating load.
2) Determine the design boiler supply temperature.
3) Determine the radiant system return temperature which is based on the design temperature drop across the radiant system.
4) Determine the design injection flow rate using the following equation:
Eq.1:
5) From the 2-Way Cv chart below, select the valve size with the closest Cv value to the injection flow rate calculated in step 4. Do not
size the 2-Way iSeries Mixing Valve based soley on pipe size.
3-Way iSeries Mixing Valve Selection
Select the 3-Way iSeries Mixing Valve based on the 3-way Pressure Drop chart below.
Sequence of Operation
Power Up and Heat Request
Whenever the iSeries-R is powered up, the LED turns on and the control starts operation. The power to the iSeries-R may be switched
through an end switch (e.g. Taco ZVC/SR style zone control) or a thermostat for intermittent operation, or the power source may be
connected directly to the iSeries-R for continuous operation.
2
Design Injection Flow Rate (US GPM) =
Design Radiant Heating Load (Btu/hr)
500 x (Boiler Supply - Radiant System Return)
1/2"
(Cv = 1.5)
PSIGPM
Flow
Ft Head
0.11
0.44 1.03 0.09 0.21 0.11 0.26
1.00 2.31 0.21 0.48 0.25 0.58
1.78 4.11 0.37 0.85 0.44 1.03
1.47 3.39 1.78 4.11
3.31 7.64 4.00 9.24
5.88 13.58
1/2
1
2
4
6
8
1 1/2
0.26
3/4"
(Cv = 3.3)
PSI
i Series: 3-Way Valve Pressure Drop
Ft Head
0.02 0.05
1"
(Cv = 3.0)
PSI Ft Head
0.03 0.06
1/2" 4.9
10.3
8.9
3/4"
1"
i Series: 2-Way Cv
Size Cv
Reset Ratio
Once the iSeries-R is powered up, it provides outdoor reset at the supply sensor location. The iSeries-R targets
a supply temperature based on the outdoor temperature measured and the Reset Ratio dial setting. The Reset
Ratio is set using the following formula:
Maximum / Minimum System Supply Temperature (DIP switch 1 & 2)
The iSeries-R has a maximum supply function used to set a maximum supply water target tem-
perature. This function helps to protect system components, such as floor coverings, by pre-
venting excessive water temperatures. The maximum target temperature is selected using DIP
switches 1 & 2.
When selecting a maximum supply target temperature of 150°F, the iSeries-R also enables a
minimum supply target temperature of 85°F. This function is typically used in staple up radiant
floor heating applications, in order to ensure enough heat delivery during mild outdoor tempera-
tures.
If the actual supply water temperature approaches the maximum or minimum system supply, the
iSeries-R modulates the valve down and the green LED flashes rapidly (reduced output).
Minimum Boiler Return Temperature (DIP switch 3)
The iSeries-R includes a boiler protection function which prevents low temperatures back to the boiler. Whenever the
boiler sensor is installed, the iSeries-R monitors the boiler return temperature and modulates the valve down when
the return temperature is near the minimum setting. The minimum setting is selected via DIP switch 3. When the
switch is turned on, the minimum temperature is set to 120°F and when the DIP is turned off the minimum tempera-
ture is 135°F.
When using low temperature boilers such as condensing or electric, the boiler minimum temperature may be disabled by powering up
the control without a boiler return sensor. Whenever the iSeries-R is being modulated towards the closed position to protect the boiler,
the green LED flashes rapidly (reduced output).
Warm Weather Shut Down (WWSD) (DIP switch 4)
When the outdoor temperature is warmer than 70°F, the iSeries-R closes. The green LED then slowly flashes during
warm weather shut down. This function may be turned on by setting the DIP switch 4 to the on position.
Valve Installation
Reset Ratio = Design Supply Temperature - 72°F
72°F - Design Outdoor Temperature
3
WARNING: Actuator must be removed from the valve body before soldering. Ball valve must be in
the full open position before soldering. Valve is shipped in the full closed position.
W
A
L
L
1 1/2" Min.
Actuator
Removal
Clearance
Figure B
Figure A:
2-way
3-way
Two Position Head Placement.
Universal Body Placement.
Valve may be installed in any position, any orientation.
3-way actuator power connections must be over the supply port.
SUPPLY RETURN SUPPLY
RETURN
MIX
MIX
1. Valve body may be installed in any position, in any orientation (see Figure A). 3-way actuator’s power connections must be over the
supply port to ensure proper flow direction (see Figure A).
2. Before mounting body, refer to Figure B and Dimensions Section for clearances.
3. Use of a lead or tin based solder with a melting point below 600°F is recommended. Do not overheat. Make sure the ball valve is in
the FULL OPEN position during soldering. Direct flame tip away from the center of the valve. Cool valve quickly with a wet rag.
4. Solder build-up on the ball valve may prevent proper opening and closing of the valve. Rotate the manual operation button several
times to loosen any possible build-up.
5. Valve body can be submerged for leak testing before the actuator is attached.
Actuator Installation / Removal
1. Valve actuator may be attached to the valve body in either direction (see Figure A). The 3-way actuator must be attached with the
power connections over the supply port to ensure proper flow direction (see Figure A).
2. Actuator removal: Remove valve actuator prior
to soldering by rotating the actuator counterclock-
wise approximately 30 degrees and lifting upward
approximately 3/4” (see Figure C).
3. To re-assemble actuator to valve body: Position
actuator such that the “D” shaped valve stem aligns
properly with the “D” shaped actuator drive cavity
(Note: The “D” shaped stem design allows for cor-
rect insertion every time). Next, slide valve stem
into actuator cavity and rotate until the actuator
slips over the valve’s locking posts (see Figure C),
once the actuator is flush with valve body, turn actu-
ator clockwise and lock into position.
Wiring and Sensor Installation
All terminals provided with the iSeries-R are removable. In order to prevent
damage to the electronics, disconnect all plugs before the power is turned on
and check voltages and sensors. Once the circuits are tested, plug in the ter-
minals.
Powering the Control
For intermittent operation, connect one side of the end switch (e.g. Taco
ZVC/SR series zone control) or thermostat to an external 24 V (ac) trans-
former. Connect the other side of the zone control’s end switch to the R ter-
minal on the iSeries-R. The C terminal must then be connected to the other
side of the transformer. For continuous operation, simply wire the transformer
directly to the R and C terminals on the iSeries-R. Ensure that no power is
present during this process.
Sensors
Do not apply power to these terminals as this will damage the iSeries-R. The
wiring terminals for the sensors may be removed for ease of installation.
Outdoor Sensor
Remove the screw and pull the front cover off the sensor enclosure.
The outdoor sensor can either be mounted directly onto a wall or in a 2” x
4” electrical box. When the sensor is wall mounted, the wiring should enter
through the back or bottom of the enclosure. Do not mount the sensor with
the conduit knockout facing upwards as rain could enter the enclosure and
damage the sensor.
WARNING: Wiring connections must be made in accordance with all applicable electrical codes.
CAUTION: To prevent electrical shock, disconnect electric power to system at main fuse or
circuit breaker box until installation is complete. When a service switch is installed, more than
one disconnect switch may be required to deenergize this device for servicing.
Figure C: Actuator Removal
Step 1
Rotate actuator counter
clockwise approximately 30
degrees
Step 2
Move actuator upward
3/4" to discharge
Locking
Post
4
In order to prevent heat transmitted through the wall from affecting the sensor reading, it may be necessary to install an insulating
barrier behind the enclosure.
The sensor should be mounted on a wall which best represents the heat load on the building (a northern wall for most buildings and
a southern facing wall for buildings with large south facing glass areas). The sensor should not be exposed to heat sources such as
ventilation or window openings. The sensor should be installed at an elevation above the ground that will prevent tampering.
Connect 18 AWG or similar wire from the outdoor sensor directly into the SENSOR COMMON and OUTDOOR terminals on the
iSeries-R. Replace the front cover of the sensor enclosure.
System Supply and Boiler Return Sensors
The sensors can be strapped directly to the pipe using a cable tie. Insulation should be placed around the sensor to reduce the effect of
air currents on the sensor measurement. The sensors should be placed downstream of a pump or after an elbow or similar fitting. This
is especially important if large diameter pipes are used because the thermal stratification within the pipe can result in erroneous sensor
readings. Proper sensor location requires that the fluid is thoroughly mixed within the pipe before it reaches the sensor.
If the System Supply Sensor is used to measure duct temperature, the sensor should be mounted in such manner that it measures the
average duct outlet temperature.
System Supply Sensor
Connect the two wires from the supply sensor directly into the SENSOR COMMON and SUPPLY terminals on the iSeries-R.
Boiler Return Sensor
Connect the two wires from the boiler return sensor directly into the SENSOR COMMON and BOILER terminals on the iSeries-R.
Troubleshooting
As in any troubleshooting procedure, it is important to isolate a problem as much as possible before proceeding. The error messages
greatly simplify troubleshooting of the iSeries-R. When the control flashes an error message, identify the fault and follow standard test-
ing procedures to confirm the problem. If you suspect a wiring fault, return to the wiring section on this brochure and carefully check all
external wiring and wiring connections.
Multi-Status LED
Adjustment of Settings
- If the outdoor temperature is cold and the building is cold, increase the Reset Ratio setting by one notch per day.
Testing the Sensors
A good quality test meter capable of measuring up to 5000 kΩ (1 kΩ = 1000 Ω) is required to measure the sensor resistance. In addition
to this, the actual temperature must be measured with a good quality digital thermometer.
First measure the temperature using the thermometer and then measure the resistance of the sensor at the iSeries-R. The wires from
the sensor must not be connected to the iSeries-R while the test is performed. The wiring terminals are easily removed by pulling them
from the iSeries-R. Using the chart below, estimate the temperature measured by the sensor. The sensor and thermometer readings
should be close. If the test meter reads a very high resistance, there may be a broken wire, a poor wiring connection or a defective
sensor. If the resistance is very low, the wiring may be shorted, there may be moisture in the sensor or the sensor may be defective.
To test for a defective sensor, measure the resistance directly at the sensor location.
5
Product Specifications
Maximum Operating Pressure: 300 PSI (2,100 kPa)
Maximum Shutoff Pressure: 125 PSI (875 kPa)
Fluid Temperature Range: 20º to 240ºF, (-7º to 115ºC) @ 135ºF (57ºC) ambient
Service: Closed systems
Hot and Chilled Water, up to 50% Glycol
Seat Leakage: Drop-Tight Close-Off
Electrical Rating: 24 VAC +/- 10%, 60 HZ
Do not exceed number of valves per transformer rating. Example:
Do not use more than 5 iSeries Mixing Valves per 40VA transformer.
Power Consumption: 7.2 Watts, 0.3 Amps
Flow Coefficients and Maximum Close-Off Pressure
Materials of Construction, Actuator
Body: High Performance Engineered Polymer
Gears: High Performance Internally Lubricated Engineered Polymer
Materials of Construction, Valve
Body: Forged Bronze
Stem: Brass
Press Ring: Brass
Ball: Brass (Chrome Plated)
Seat: Modified Teflon
O-rings: EPDM
Dimensions
6
Ordering Information
Replacement Parts
Part # Description
9300-2044RP Strap-on Sensor
9300-2052RP Outdoor Sensor
iT024Q6A1 Outdoor Reset Actuator
iU024Q6A1 Setpoint Actuator
Notes
7
Do It Once. Do It Right.™
TACO, INC., 1160 Cranston Street, Cranston, RI 02920 Telephone: (401) 942-8000 Fax:(401) 942-2360
TACO (Canada), Ltd., 6180 Ordan Drive, Mississauga, Ontario L5T 2B3 Telephone:(905) 564-9436 Fax:(905) 564-9436
Visit our web site at: http://www.taco-hvac.com
Copyright 2003 TACO, INC.
Portions Copyright 2003
tekmar Control Systems Ltd.
tekmar Control Systems.Inc.
Printed in USA
8
LIMITED WARRANTY STATEMENT
Taco, Inc. will repair or replace without charge (at the company’s option) any product or part which is proven defective under normal
use within one (1) year from the date of start-up or one (1) year and six (6) months from date of shipment (whichever occurs first).
Taco, Inc. will repair or replace without charge (at the company’s option) any i Series Mixing Valve body that is proven defective under
normal use within three (3) years from the date of start-up or three (3) years and six (6) months from date of shipment (whichever
occurs first).
In order to obtain service under this warranty, it is the responsibility of the purchaser to promptly notify the local Taco stocking distribu-
tor or Taco in writing and promptly deliver the subject product or part, delivery prepaid, to the stocking distributor. For assistance on
warranty returns, the purchaser may either contact the local Taco stocking distributor or Taco. If the subject product or part contains
no defect as covered in this warranty, the purchaser will be billed for parts and labor charges in effect at time of factory examination
and repair.
Any Taco product or part not installed or operated in conformity with Taco instructions or which has been subject to misuse, misapplica-
tion, the addition of petroleum-based fluids or certain chemical additives to the systems, or other abuse, will not be covered by this
warranty.
If in doubt as to whether a particular substance is suitable for use with a Taco product or part, or for any application restrictions, consult
the applicable Taco instruction sheets or contact Taco at [401-942-8000].
Taco reserves the right to provide replacement products and parts which are substantially similar in design and functionally equivalent
to the defective product or part. Taco reserves the right to make changes in details of design, construction, or arrangement of materials
of its products without notification.
TACO OFFERS THIS WARRANTY IN LIEU OF ALL OTHER EXPRESS WARRANTIES. ANY WARRANTY IMPLIED BY LAW
INCLUDING WARRANTIES OF MERCHANTABILITY OR FITNESS IS IN EFFECT ONLY FOR THE DURATION OF THE EXPRESS
WARRANTY SET FORTH IN THE FIRST PARAGRAPH ABOVE.
THE ABOVE WARRANTIES ARE IN LIEU OF ALL OTHER WARRANTIES, EXPRESS OR STATUTORY, OR ANY OTHER WAR-
RANTY OBLIGATION ON THE PART OF TACO.
TACO WILL NOT BE LIABLE FOR ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES RESULTING FROM
THE USE OF ITS PRODUCTS OR ANY INCIDENTAL COSTS OF REMOVING OR REPLACING DEFECTIVE PRODUCTS.
This warranty gives the purchaser specific rights, and the purchaser may have other rights which vary from state to state. Some states
do not allow limitations on how long an implied warranty lasts or on the exclusion of incidental or consequential damages, so these
limitations or exclusions may not apply to you.
Table of contents
Other Taco Control Unit manuals
Taco
Taco Zone Sentry User manual
Taco
Taco FloodBreaker Manual
Taco
Taco 5123-WH-N User manual
Taco
Taco HR Series Specifications
Taco
Taco Comfort Solutions 5000-3 Series User manual
Taco
Taco SR501 User manual
Taco
Taco ZVC404-EXP-4 User manual
Taco
Taco Zone Sentry Series User manual
Taco
Taco 102-111 User manual
Taco
Taco 5000-HX Series User manual
Popular Control Unit manuals by other brands
Freescale Semiconductor
Freescale Semiconductor Kinetis TWR-K24F120M quick start guide
Swagelok
Swagelok IPT Series manual
Jabra
Jabra 14201-20 - How to connect
Fisher
Fisher ACE95Sr instruction manual
Interpump Group
Interpump Group KR1 operating instructions
Communication Devices
Communication Devices PCM620 user manual
