nVent RAYCHEM H57510 Hot Water Temperature Maintenance System Instruction manual

Hot Water Temperature Maintenance –
HWAT System
This step-by-step design guide provides the tools necessary to design a
nVent RAYCHEM Hot Water Temperature Maintenance System (HWAT).
For additional information, contact your nVent representative or
call (800) 545-6258. Also, visit our website at nVent.com/RAYCHEM.
Table of Contents
INTRODUCTION ..................................................................................... 1
Typical Applications .............................................................................................................. 2
Approvals and Code Compliance ...................................................................................... 2
Safety Guidelines .................................................................................................................. 2
Ground Fault Protection ....................................................................................................... 3
Scald Protection .................................................................................................................... 3
Design Requirements ........................................................................................................... 3
SYSTEM OVERVIEW ............................................................................... 3
HWAT Electronic Controllers .............................................................................................. 4
HWAT Heating Cables .......................................................................................................... 4
RayClic, FTC and HWT Connection Kits .......................................................................... 5
DESIGN GUIDELINES ............................................................................. 5
Before You Begin ................................................................................................................... 6
INTRODUCTION
nVent RAYCHEM Hot Water Temperature Maintenance (HWAT) systems are a smart alternative to conventional recirculation
systems for meeting modern Green energy and plumbing code that save water, energy and improve water quality.
HWAT systems consist of an electronic controller, self-regulating electric heating cables, pipe insulation and easy-to-install
connection kits. The heating cables are attached to hot water supply pipes to compensate for heat loss and maintains water
temperature to point of use, thus eliminating the need for return piping, balancing valves and associated equipment.
When used in concert with conventional designs, it can optimize the overall efficiency of the hot water delivery system.
While our HWAT 208-277 V solutions have been delivering the benefits of Hot Water Temperature Maintenance immediate hot
water at the tap, reduced water waste, and space and cost savings in mixed use high-rise buildings, schools and hotels for
quite some time, our new HWAT 120 V system now offers the added value of a more residential / multi-family building-friendly
“behind-the-meter” application.
When submetering is required by code, a conventional design would typically require a water heater installation for every unit
in the building or a complex circulation system. A HWAT 120 V system, along with a central water heating unit, delivers a more
economical solution that enables efficient and inexpensive metering and billing for each individual unit's hot water usage
without complex system design and installations.
Additionally, our high quality HWAT systems improve water quality by meeting ASHRAE 188 Legionella control guidelines.
HWAT systems are eligible for LEED points for both Energy Savings and Innovation in Design.
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Typical Applications
The HWAT system is designed to be installed and operated in commercial
and residential buildings. Table 1 shows typical HWAT applications, desired
maintain temperatures when nVent RAYCHEM HWAT-P1 heating cable is used in
conjunction with the nVent RAYCHEM HWAT-ECO-GF, or when nVent RAYCHEM
HWAT-R2 heating cable is used in conjunction with the nVent RAYCHEM
HWAT-ECO-GF or ACS-30 controllers.
Table 1 Typical HWAT Applications
Application
Desired maintain temperature
Hospitals, nursing homes
105°F (40°C)
Schools, prisons, some hospitals
115°F (45°C)
Offices, hotels, homes and apartments
125°F (50°C)
Kitchens, laundries
140°F (60°C)*
* with HWAT-R2 only.
This design guide covers standard HWAT applications which must meet
the following conditions:
• Installed on copper or rigid plastic pipes
• Insulated in accordance with the insulation schedule shown in Table 6
• Powered at 120 V using HWAT-ECO-GF or at 208 - 277 V using the ACS-30 or
HWAT-ECO-GF controller
• Operated indoors where the ambient temperature is relatively constant and
between 60°F (15°C) and 80°F (27°C)
If your application does not meet the above conditions, contact your
nVent representative for custom design assistance.
Approvals and Code Compliance
The HWAT system components are c-UL-us Listed in nonhazardous locations.
HWAT-P1 and HWAT-R2 heating cables, RayClic, HWT and FTC-HST-PLUS connection kit and the
HWAT-ECO-GF controller are c-UL-us Listed and the ACS-CRM and the ACS-CRMS controllers are c-UL-us
certified (ACS-UIT3) to US and Canadian standards for us in non-hazardous locations. Refer to the specific
product data sheets for details.
The HWAT system is designed in accordance with the following international and
national codes:
• International Plumbing Code
• International Building Code
• International Energy Conservation Code
• National Standard Plumbing Code
• National Electrical Code
• Canadian Electrical Code
• ANSI/ASHRAE Standard 188-2018 - Legionellosis: Risk Management for Building
Water Systems
• CIBSE TM13-2013 Minimising the Risk of Legionnaires Disease
Additionally, our HWAT solution has numerous state and local code approvals.
Contact your nVent representative for further information. Due to its potential
to reduce energy usage and greenhouse gas emissions, HWAT solutions are
eligible for LEED points.
Safety Guidelines
The safety and reliability of any heat-tracing system depends on the quality of the
products selected and on proper design, installation, and maintenance. Incorrect
design, handling, installation, or maintenance of any of the system components
can cause underheating or overheating of the pipe or damage to the heating cable
system and may result in system failure, electric shock, or fire. The guidelines
and instructions contained in this guide are important. Follow them carefully to
minimize these risks and to ensure that the HWAT system performs reliably.
Pay special attention to safety warnings identified as
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WARNING.
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Ground Fault Protection
To minimize the danger of fire from sustained electrical arcing if the heating
cable is damaged or improperly installed, and to comply with nVent requirements,
agency certifications, and national electrical codes, ground fault equipment
protection must be used on each heating cable branch circuit. Arcing may not
be stopped by conventional circuit breakers. The HWAT-ECO-GF and ACS-30
controllers meet the electrical code requirements for ground fault equipment
protection.
Scald Protection
WARNING: Water temperature above
130°F (55°C) presents a significant risk of
personal injury and/or death and requires
that scald protection measures be
implemented for safe use.
HWAT systems present an increased risk of scalding due to the high water
temperature. Pay special attention to the scald warning to the left.
Design Requirements
To comply with warranty requirements, the design and installation of the HWAT
system must be in accordance with this guide and the additional documents
listed below:
• HWAT-ECO-GF Installation and Operations Manual (H60223)
• HWAT System Installation and Operations Manual (H57548)
• Rayclic Connection Kit Installation Instructions (H55388 and H55092)
Installation documents are shipped with the respective products and are also
available on our website at nVent.com/RAYCHEM.
SYSTEM OVERVIEW
A complete HWAT system includes one or more HWAT-ECO-GF or ACS-30
electronic controllers, HWAT-P1 or HWAT-R2 heating cable and nVent RAYCHEM
RayClic connection kits. Fig. 1 illustrates a typical HWAT system. The key
components of the system will be described in this section.
Temperature
sensor
Insulation
180°
Heating
cable
End
seal
Glass
tape
Heating
cable
Pipe
temperature
sensor
Thermal
insulation
ETL
label
Splice
Tee
Controller
er
pow ion
To tribut
dis el
pan
Note: Pipe insulation
removed for clarity.
All pipes must be fully
insulated
Power
connection
Fig. 1 Typical HWAT heating cable system
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HWAT Electronic Controllers
The HWAT-ECO-GF electronic controller is designed for use with a single circuit of
HWAT-P1 or HWAT-R2 self-regulating heating cable. For large hot water systems
the ACS-30 distributed controller is available, refer to the ACS-30 data sheet
(H58261) for more information. The HWAT-ECO-GF provides a variety of features
and control options, listed below, for your hot water temperature maintenance
system.
Fig. 2 HWAT-ECO-GF controller
• Equipment rated ground fault protection built-in
• Intuitive set-up and programming, includes a 5" inch color touch screen
• Flexible temperature control of hot water temperature maintenance systems
• Energy savings through an integrated function that lowers the maintain
temperature during hours of low water consumption
• Heat-up cycle function that increases the water temperature of the hot water
in the pipes
• Alarm relay to signal power, temperature or communication problems
• Hot water storage and pipe temperature monitoring with high and low
temperature alarms and automatic system shut down
• Seven pre-defined building timer programs that can be customized by the user
• Program in advance in power-off mode by using external power bank/charger
and USB connection
HWAT Heating Cables
HWAT-P1 or HWAT-R2 self-regulating heating cables are installed on hot water
supply pipes underneath standard pipe insulation. The heating cable adjusts its
power output to reduce the effect of ambient temperature swings. The HWAT
system provides continuous hot water temperature maintenance while eliminating
the need for a recirculation system.
Modified polyolefin outer jacket
Tinned-copper braid
Polymer-coated aluminum wrap
Modified polyolefin inner jacket
Self-regulating conductive core
Nickel-plated copper bus wires
Fig. 3 HWAT heating cable
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HWAT heating cables provide the following features:
• Adjust power output to reduce the variations in water temperature
• Can be cut to length, spliced, teed, and terminated in the field
• Designed for use with the HWAT-ECO-GF or ACS-30 controller
RayClic, FTC and HWT Connection Kits
The RayClic connection system is a simple, fast, and reliable set of connection kits
developed for use with HWAT self-regulating heating cables. RayClic connection
kits reduce installation time, lowering the total installed cost of the HWAT system.
nVent RAYCHEM HWT-P and FTC-HST-PLUS heat shrink kits may also be used.
Alternate
lighted end seal
RayClic-PC
powered connection
RayClic-LE
lighted end seal
RayClic-S
splice
RayClic-E
end seal
RayClic-PT
powered
tee
RayClic-PS
powered
splice
RayClic-X
cross tee
HWAT
heating cable
RayClic-T
tee
Alternate
connection kits
Fig. 4 RayClic connection kits
DESIGN GUIDELINES
This section describes the seven steps necessary to design an HWAT system:
1
Select the heating cable
2
Lay out the heating cable
3
Select connection kits and accessories
4
Finalize circuit length
5
Select control configurations
6
Select thermal insulation
7
Complete Bill of Materials
To assist you with the design, we will carry two design examples through this
process. The example details are listed below each step in red.
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Example 1
Example 2
An elementary school where 115°F
(46°C) is the desired maintain
temperature and no heat-up cycle
is required. Piping layout shows
approximately 300 ft of pipe with two
branches at the same location.
A medium security prison where
115°F (46°C) is the desired maintain
temperature and a 140°F (60°C)
heat-up cycle is required. Piping
layout shows approximately 700 ft of
pipe with two branches at different
locations.
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Before You Begin
Before you begin designing your HWAT system, gather this necessary information:
• Desired maintain temperature
• Indoor ambient temperature
• Supply voltage
• Piping layout
• Total pipe length
• Pipe diameters
HWAT System Design
Step 1 Select heating cable
2. Lay out the
heating cable
Use Table 2 to select the appropriate system temperature setting. For more
information on heat-up cycles, refer to the HWAT-ECO-GF Installation and
Operations Manual (H60223) or ACS-30 Programming Guide (H58692).
3. Select connection
kits and accessories
Heating Cable Catalog Number
1. Select heating cable
4. Finalize circuit
length
5. Select control
configuration
6. Select insulation
7. Complete Bill of
Materials
Before beginning, take a moment to understand the structure underlying heating
cable catalog numbers. You will refer to this numbering convention throughout the
product selection process. Your goal is to determine the catalog number for the
product that best suits your needs.
Catalog Number: HWAT-P1 or R2
Voltage P1 = 120 V
R2 = 208, 240, 277 V
Fig. 5 Heating cable catalog number
Record the following information:
• Desired maintain temperature (°F/°C)
_____________
• Indoor ambient temperature (°F/°C)
_____________
• Supply voltage (V)
_____________
• Heat-up cycle (Yes/No)
_____________
• Temperature (°F/°C)
_____________
Example: Heating Cable Selection
Example 1
Example 2
Desired maintain temperature
115°F (46°C)
115°F (46°C)
Ambient temperature
70°F (21°C)
70°F (21°C)
Supply voltage
208 Vac
208 Vac
Heat-up cycle required
No
Yes
Heat-up cycle temperature
n/a
140°F (60°C)
Table 2 HWAT System Temperature Range
WARNING: Water temperature above
130°F (55°C) presents a significant risk of
personal injury and/or death and requires
that scald protection measures be
implemented for safe use.
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HWAT-ECO-GF
ACS-30
Minimum maintain temperature
105°F (40°C)
100°F (38°C)
Maximum maintain temperature
(HWAT-R2)
140°F (60°C)
150°F (66°C)
Maximum maintain temperature
(HWAT-P1)
130°F (54°C)
Heat-up cycle*
>140°F (60°C)
>150°F (66°C)
* For additional information on heat-up cycles, refer to the “Expanded HWAT-ECO-GF
Electronic Controller Capabilities” section of the HWAT-ECO-GF Installation and Operations
Manual (H60223).
Heating Cable Selection
Example
Heating cable selected
HWAT-R2
RAYCHEM-DG-H57510-HWATHotWaterTempMaint-EN-2310
HWAT System Design
Step 2 Lay out the heating cable
1. Select heating cable
2. Lay out the
heating cable
3. Select connection
kits and accessories
4. Finalize circuit
length
5. Select control
configuration
6. Select insulation
7. Complete Bill of
Materials
The piping layout of your building may require more than one HWAT circuit. To
determine the number of circuits, group your piping by maintain temperature and
location, a step that may require you to consult the plumbing and/or electrical
engineer. Calculate the total length of pipe in each group, allowing one foot of heating
cable for each foot of pipe. The length of heating cable in each group must not
exceed the circuit lengths listed in Table 3.
In Step 4, you will calculate the additional cable required to install the connection
kits. This will increase the total length of heating cable and may require the need
for additional circuits.
Table 3 Maximum Circuit Length
Circuit Lengths
Circuit breaker size (Amps)
HWAT-P1 @120 V ft (m)
HWAT-R2 @208-277 V ft (m)
10
125 (38)
15
195 (59)
250 (75)
20
276 (84)
330 (100)
30
395 (120)
500 (150)
Note: Assumes a minimum water temperature of 50°F (10°C) at startup
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Example: Lay out Circuits
Example
HWAT heating cable selected
HWAT-R2
Length of pipe
700 ft
Number of circuits
2
Circuit breaker size
30 Amp
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HWAT System Design
Step 3 Select connection kits and accessories
HWAT systems are approved and warranted only as a complete system. The
appropriate RayClic, FTC or HWT connection kits must be used. Use Table 4 to
select the connection kits and accessories necessary for your HWAT system.
Refer to the RayClic Connection System data sheet (H57545) and the FTC Heat
Shrinkable Connection Kits Datasheet (H58159) in the Technical Data section for
more information on the products.
1. Select heating cable
2. Lay out the
heating cable
3. Select connection
kits and accessories
4. Finalize circuit
length
The appropriate numbers of end seals are included with each connection kit.
5. Select control
configuration
Table 4 Connection Kits and Accessories
6. Select insulation
7. Complete Bill of
Materials
No. of end
seals included
Catalog number
Description
Quantity required
RayClic-PC
Power connection kit
One -PC, -PS, -PT
required per circuit
1
Powered splice kit
One -PC, -PS, -PT
required per circuit
2
Powered tee kit
One -PC, -PS, -PT
required per circuit
3
RayClic-S
Splice kit
As required*
0
RayClic-X
Cross kit
As required
2
RayClic-T
Tee kit
1
RayClic-E
End seal kit
As required
As required for
spares
HWT-P
Heat shrink power
connection kit
RayClic-PS
RayClic-PT
GT-66
Heat shrink splice or
tee kit
Glass tape
ETL
Electric traced tape
FTC-HST-PLUS
1
One required per
circuit
1
As required
0
1 roll per 50 ft of pipe
1 label per 10 ft of
pipe
n/a
n/a
* To minimize cable waste, nVent recommends that one RayClic‑S be ordered for every
500 feet of cable.
Example: Select Connection Kits and Accessories
Example
Piping layout determined that the following
2 RayClic-PC
connection kits and accessories are required.
2 RayClic-T
14 GT-66
70 ETL
HWAT System Design
Step 4 Finalize circuit length
1. Select heating cable
2. Lay out the
heating cable
3. Select connection
kits and accessories
4. Finalize circuit
length
5. Select control
configuration
6. Select insulation
7. Complete Bill of
Materials
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Additional cable is required for future access at each connection kit. Add the
additional cable, as detailed in Table 5, to the estimated circuit lengths from
Step 2. Confirm that the maximum lengths shown in Table 3 have not been
exceeded. If your circuit lengths are greater than those shown, reconfigure
your heating cable layout to allow for additional circuits.
Table 5 Additional Cable Required for Each Connection Kit
Connection
kit name
No. of cable
connections/kit
Cable length/
connection
ft (m)
Total cable length
(service loop)
ft (m)
RayClic-PC
1
2.0 (0.6)
2.0 (0.6)
RayClic-S
2
1.0 (0.3)
2.0 (0.6)
RayClic-T
3
1.0 (0.3)
3.0 (0.9)
RayClic-X
4
1.0 (0.3)
4.0 (1.2)
RayClic-PS
2
1.5 (0.5)
3.0 (0.9)
RayClic-PT
3
1.3 (0.4)
4.0 (1.2)
RayClic-E
1
n/a
n/a
HWT-P
1
2.0 (0.6)
FTC-HST-PLUS
2 or 3
1.0 (0.3)
2.0 (0.6)
2.0 (0.6) for a splice
3.0 (0.9) for a tee
RAYCHEM-DG-H57510-HWATHotWaterTempMaint-EN-2310
Example: Finalize Circuit Length
Example
Circuit 1*
Circuit 2*
350 ft
350 ft
RayClic-PC
2 ft
2 ft
RayClic-T
3 ft
3 ft
Length of heating cable per circuit
Additional cable required
RayClic-X
Total length of heating cable required
n/a
n/a
355 ft
355 ft
* In this example, the circuits were evenly divided. Equal circuit lengths are not required.
HWAT System Design
Step 5 Select control configuration
For single circuit applications, choose the HWAT-ECO-GF controller.
For multi-circuit applications, choose the ACS-30 controller.
1. Select heating cable
2. Lay out the
heating cable
3. Select connection
kits and accessories
Example: Select Control Method
4. Finalize circuit
length
5. Select control
configuration
6. Select insulation
Example 1
Example 2
Type
Individual circuit
Multi-circuit
Number of circuits
1
up to 260
Controller
HWAT-ECO-GF
ACS-30
7. Complete Bill of
Materials
HWAT System Design
Step 6 Select insulation
1. Select heating cable
2. Lay out the
heating cable
3. Select connection
kits and accessories
4. Finalize circuit
length
Select the size of thermal insulation from Table 6. You will need to know the length
and diameter of each pipe used in your application.
For pipes 1¼ inches and smaller, use insulation that is oversized by ¼ inch to
allow room for insulating over the heating cables. Table 6 specifies IPS (Iron Pipe
Size) insulation, which has a greater inner diameter than CTS (Copper Tube Size)
insulation.
5. Select control
configuration
6. Select insulation
7. Complete Bill of
Materials
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For pipes 3 inches and larger, the thickness of insulation can either be equal to
the pipe diameter with a single heating cable or 1/3 the pipe diameter with two
heating cables. For example, a 6 inch pipe with 6 inches of insulation and one run
of heating cable is equivalent to a 6 inch pipe with 2 inches of insulation and two
runs of heating cable.
Table 6 Fiberglass Insulation Selection
Copper pipe size (in)
IPS insulation size (in)
Insulation thickness (in)
½
¾
½
¾
1
1
1
1½
1
1¼
1½
1½
1½
1½
1½
2
2
2
2½
2½
2½
3
3
3
Note: For pipes 3 inches and larger, the thickness of insulation can be equal to the
pipe diameter with one run of heating cable or 1/3 the pipe diameter with two runs
of heating cable.
Example: Select Insulation
Example 1
Example 2
HWAT System Design
Copper pipe size
(in)
¾
IPS insulation size
(in)
1
Insulation thickness
(in)
1
1
1¼
1
1½
1½
1½
1
1¼
1
2
2
2
2½
2½
2½
Step 7 Complete bill of materials
1. Select heating cable
2. Lay out the
heating cable
You are now ready to compile a Bill of Materials. Using the design results, detail
each item as shown in Table 7 below. Fig. 5 illustrates a complete typical HWAT
system.
3. Select connection
kits and accessories
4. Finalize circuit
length
5. Select control
configuration
6. Select insulation
7. Complete Bill of
Materials
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RAYCHEM-DG-H57510-HWATHotWaterTempMaint-EN-2310
Temperature
sensor
Insulation
180°
Heating
cable
End
seal
Glass
tape
Heating
cable
Pipe
temperature
sensor
Thermal
insulation
ETL
label
Tee
Controller
er
pow ion
To tribut
dis el
pan
Splice
Note: Pipe insulation
removed for clarity.
All pipes must be fully
insulated
Power
connection
Fig. 6 Typical HWAT heating cable system
RS-485
RTD
Pipe
Heating
cable
To heating cable power
distribution panel
ACS-UIT3
ACS-PCM2-5
Fig. 7 Typical configuration for the ACS-30 system
Table 7 Bill of Materials (Example)
RAYCHEM-DG-H57510-HWATHotWaterTempMaint-EN-2310
Description
Catalog number
Quantity
HWAT heating cable
HWAT-R2
706 ft
Power connection kit
RayClic-PC
2
Tee connection kit
RayClic-T
2
Controller
HWAT-ECO-GF
2
Attachment tape
GT-66
12 rolls
Labels
ETL
70
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