Available Up To 54 KW in Single or
Three Phase Voltages
The Hubbell Model MTX Tankless Water
Heater is the perfect choice for Marine
applications.
SAVES WEIGHT
✓
SAVES SPACE
✓
SAVES TIME
✓
Marine Approvals
■ American Bureau of
Shipping (ABS) Type
Approved
■ ABS Approval eliminates
costly delays and
uncertainties during ship
inspection
Heavy Duty Construction
■
Simple to specify
and easy to operate
■ Factory wired electrical
controls provide troublefree installation and
operation
Weight and Space Saving
■
Signicantly reduces weight
and saves space compared to
storage tank water heaters
■
On demand heating
eliminates costly and
cumbersome storage tanks
■
Instantaneous design reduces
stand-by heat loss and lowers
operating costs
Reliable
■
Engineered for your
specic application
to ensure reliable operation
■ Constructed with high grade
materials to ensure long
operating life
Tankless On Demand Water Heater for
Marine Applications
The Hubbell MTX Tankless model is a highly reliable and easily
maintained electric water heater designed for operation in a
marine application. The Hubbell MTX Tankless is compact,
highly efcient, takes up minimal space, and reduces operating
costs. Hubbell’s vast experience, meticulous engineering, and
advanced manufacturing processes ensure that you can rely on
the MTX Tankless for your water heating needs in even the most
demanding and critical applications. It makes sense to specify
and install a Hubbell MTX Tankless model for your heating
requirements, and as the owner you will be provided with a
quality product that is long lasting, trouble-free, and energy
efcient.
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High Efciency Compact
Electric Tankless
Water Heater
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ANSI/NSF 5
ISO 9001:2008
The Electric Heater Company
P.O. Box 288 ■ Stratford, CT 06615-0288
Phone: 203- 378-2659
info@hubbellheaters.com
■
FAX: 203- 378-3593
■
www.hubbellheaters.com
ISO
Page 2
Marine Products Division
Hubbell Tankless Features
How It Works
The Hubbell Model MTX electric tankless water heater contains high powered heating elements that
heat water only when there is demand for hot water. When hot water is needed, a built in ow sensor
measures the exact ow rate, and that data combined with temperature readings at the heater’s inlet
and outlet are processed by the electronic temperature controller. This data is continuously transmitted
to the temperature controller, which constantly calculates the precise amount of power (kW) needed to
achieve the desired temperature. A zero cross over ring signal is sent to the fast acting triacs in order to
modulate the heating elements to the precise level needed to meet demand. The Hubbell tankless heater
uses only as much power as is needed, while delivering accurate and consistent hot water temperature.
Heater Overview - 3 Element Model Shown
Stainless Steel Exterior
Heating Chamber
All copper and bronze
construction
Outlet Thermistor
Provides feedback to ensure
consistent outlet temperature
HOT WATER OUT
Drain Port
Simplies maintenance
COLD WATER IN
Dielectric Unions
Simplies plumbing installation
Flow Meter
Measures the exact ow rate which
enables the control system to provide
perfectly matched heating power with demand
Power Distribution Block
Provides a heavy duty single point
power connection
(Only Required on Certain Models)
Fully disengages the heating
elements in a fault condition
Sleek design and corrosion resistant
Magnetic Contactor
(Only Required on 3 Phase Units)
for long life
Control Transformer
Step down transformer provides
240 Volt control circuit power
(Only Required on Models over 240 Volt)
Commercial Quality
Heating Elements
Incoloy sheathed for long life
Safety Thermostats
Auto resetting Hi-Limit thermostats
protect against over heating
Solid State Switches
Modulate heating elements 0-100%
to ensure accurate and consistent
temperature and long element life
Inlet Thermistor
Senses cold water temperature
Numeric Digital Display
Electronic Temperature Controller
is adjustable in 1° increments in either
°F or °C
Bulkhead Mounting
Securely mounts to the bulkhead and
saves valuable deck space
Tankless Model MTX Standard Specications
Heating Chamber:
Capacities:
Mounting:
Voltages:
Phase:
Power Factor:
Thermal Efciency:
Copper and Bronze
5 thru 54 kW
Bulkhead Mounted
208 thru 600 Volt 50/60 Hz
Φ
and
3
(balanced)
Φ
1
0.999
98% +
Inlet/Outlet Size:
MTX:
MHX:
3
/4" Dielectric Union Copper Sweat
1" Dielectric Union Copper Sweat
Min/Max Flow:
MTX:
MHX:
2
Thermostat Range:
0.2 GPM Min, 8.0 GPM Max
0.5 GPM Min, 40 GPM Max
32 -194°F / 0-90°C
Hi-Limit:
Design WP:
Design TP:
Elements:
Standby Power:
Chamber
Electrical
Warranty:
Enclosure:
Approvals:
200°F (Fixed)
100 psi
300 psi
Incoloy 800
< 3 Watts
5 Year
1 Year
Stainless Steel Brushed Finish
ABS, cULus, UL EPH ANSI/NSF 5
Page 3
Marine Products Division
Technical Features
Temperature Controller
A sophisticated electronic temperature controller with LED digital display provides the user interface. The temperature controller
processes all ow and temperature data and calculates the precise amount of power needed to meet demand.
Operator Control Capabilities
✓
Power Limiting:
✓
Diagnostics:
✓
Cost Calculator:
✓
Temperature Control:
Full Heater Modulation
Each heating element is switched on/off using a fast acting solid state triac with zero cross over ring control. This switching
schema provides full modulation of each heating element, ensuring that the precise amount of heat is added to meet demand. To
improve operating efciency and component longevity, each triac is mounted to a heat sink located on the incoming supply piping
so that heat generated by the triac during the switching process is dissipated into the water.
Proper Power Integrity
All Hubbell tankless water heaters, including all 3 phase models, are engineered to operate as a balanced load and operate
at 0.999 Power Factor. All Hubbell 3 phase models are designed for 3 wire (3 live, 1 ground) and 4 wire power systems and draw
equal current across all conductors to maintain the power integrity of the users electrical system. Hubbell does not recommend the
use of heaters that operate as an unbalanced load, as is common with staged heaters designed for star systems (3 live, 1 neutral, 1
ground) that require use of the neutral leg. All load switching in Hubbell tankless models is performed as zero cross over, eliminating
phase angle ring interference and associated EMI issues.
Full Resource Staging
The Hubbell tankless control schema ensures that usage is equalized across all heating circuits. To achieve this, once the
controller has calculated the precise amount of kW required, all circuits are energized in a staggered fashion such that each circuit is
proportionally and independently energized and then time staggered between circuits. This Full Resource Staging Schema reduces
EMI output, increases component longevity, and provides highly accurate and consistent hot water temperatures. For three phase
models, all circuits are fully modulated and synchronized to operate as a balanced load.
Shipboard Machinery Control Integration
Remote Control: Ability to remotely enable or inhibit the heating operation of the unit using one of the following two methods:
1. Customer supplied 24VDC signal is user congured for either Inhibit Mode or Normal Operation Mode.
2. Customer supplied volt free contact is user congured for either Inhibit Mode or Normal Operation Mode.
Priority Control: An integrated SPDT potential free dry contact (NO/NC 10A @ 240VAC) energizes when the unit is heating and
Allows the operator to reduce the power consumption by any percentage to provide installation and
operational flexibility and savings.
Display inlet and outlet temperatures, flow rate and error codes to assist in troubleshooting.
Determine the exact cost of operating the heater. Input your cost per KW·Hr and the controller displays total
KW·HRs consumed, total cost of operation, and total hot water usage (shown in gallons or liters).
Set the digital display to the desired water temperature in °F or °C. Fully adjustable in 1° increments from
32-194°F (0-90°C). A user adjustable +/- 3° calibration feature provides additional control for superior accuracy.
de-energizes when not heating. This feature is useful when it is desirable to give the water heater priority over
another electrical load to ensure that both are not operational at the same time.
Options
A. High ow construction specify model MHX for up to
40 GPM ow (min 0.5 GPM actuation).
B. Type 316L stainless steel heating chamber for added
corrosion resistance.
C. Special construction features available. Consult factory.
D. Inlet/Outlet assembly simplies installation and includes
unions, shut offs, checkvalve, drain and pressure
relief valve.
E. NEMA 4x construction when heater is located in a wet
environment. Overall dimensions 24" x 20" x 6"
F. Heating chamber built to ASME Section VIII and "UM"
stamped.
Manifold Assembly Option
Single point connection
for redundancy and high
demand applications.
G. Remote Control Display allows the heater to be installed in remote
location. The 3" x 5" NEMA 4 display enclosure can be located up
to 250' from the heater and gives the operator full remote control
and monitoring capabilities.
H. Optional Inlet/Outlet union for connection to IPS pipe sizes.
Specify customer connection as sil-braze or NPT.
I. Special construction for use onboard Military Naval Vessels
including shock, vibration and EMI qualications.
J. Factory supplied manifold single point connection for redundancy
and high demand applications.
K. Right Hand orientation Inlet/Outlet on right hand side of unit.
F Temperature Rise (oF∆T)MAX Amps (at 100% heater output)
3 Phase Voltages1 Phase Voltages
∆T
208V240V440V480V600V208V240V
Sizing Formulas
Step 1
Variables To Solve For:
KW Requirement:
Temperature Rise:
Flow Rate:
Step 2
Choose the Tankless model with the KW rating which meets the peak
demand (GPM) and required temperature rise (
Step 3
Choose the voltage and phase power supply available. Note the total
amperage draw of the unit and verify availability.
Solve for the unknown using formulas below.
GPM x oF∆T x 0.1465 = KW
KW x 6.824 ÷ GPM = oF∆T
KW x 6.824 ÷ oF∆T = GPM
o
F∆T) for your application.
Model Number Designation
MTX
—
Voltage De-Rating Factors
Rated Voltage Applied VoltageDe-Rating Factor
600 V575 V92%
600 V550 V84%
480 V460 V92%
240 V230 V92%
240 V220 V84%
When the actual supply voltage (applied voltage) is different
than the design voltage (rated voltage) the resulting KW output
will be affected. Please see the chart for typical voltage
de-rating factors, or use the following formula.
Applied Voltage
Rated Voltage
2
X Rated KW = KW output at applied voltage
2
Example: MTX027-3T5
A Hubbell tankless electric water heater rated at 27 KW with
■
Step 1
Base Model No.
MTX = 8 GPM Max
MHX = 40 GPM Max
■
Step 2
KW Rating:
5 thru 54KW
(005 - 054)
■
Step 3
Number of
Heating Elements:
2
3
6
a total of 3 heating elements when powered with 440 volt, three
phase, 60 Hz.
Option Note
Any and all optional equipment for a tankless model heater must be called out in the
written specications. A model number in and of itself does not reect any optional
equipment selected.
■
Step 4
Voltage / Phase / Hz:
RS = 208-1-60
R = 208-3-60
S = 240-1-60
T = 240-3-60
T3 = 380-3-50/60
T7 = 415-3-50/60
T5 = 440-3-60
T4 = 480-3-60
T6 = 600-3-60
5
Page 6
Model MTX TANKLESS
MadeintheU.S.A.
Master Specication
General
Heating Chamber
Heating Capacity
Electrical
SHIP NAME
SHIPYARD
ENGINEER / NAVAL ARCHITECT / SPECIfIER
CONTRACTOR / SHIP CHANDLER
Provide a quantity of packaged type instantaneous electric tankless water heater(s) Model No.
MTX
as manufactured by HUBBELL Electric Heater Co., Stratford, CT. The
entire unit is packaged ready for plumbing and electrical service connections and shall be Type Approved by
the American Bureau of Shipping (ABS) and bear the
cULUs listing mark certifying the entire unit to UL499,
UL EPH Sanitation listed to ANSI/NSF Standard 5 and CSA C22.2 No. 64-M91 (single phase units) and CSA
C22.2 No. 88 (three phase units).
The heating chamber shall be all sil-brazed copper and bronze construction. (
Optional Specication: Type
316L Stainless Steel ). A plastic heating chamber shall not be acceptable. Water heater heating chamber
shall be rated for a maximum allowable working pressure of 100 psi. The heating chamber and all
electrical controls shall be completely enclosed in a heavy gauge stainless steel case.
The tankless heater shall be rated at
rise (
° to °F ). Heaters that require the use of a ow restrictor or specialized aerator
KW which will heat GPM of water at °F
shall not be acceptable.
The tankless heater shall be designed to operate at
volts, phase, 50/60Hz balanced
power and shall draw equal amperage across all phases at all times. For 3 phase heaters, power shall be a 3
wire (3 live, 1 ground) or a 4 wire (3 live, 1 neutral, 1 ground) system that does not require a neutral leg. The
heater will draw
amps only when operating at full power. The immersion heating elements shall be
high quality incoloy sheathed and sized to obtain the rated capacity. Each element is to be operated using
zero cross over solid state controls. The heating elements shall be fully modulated from 0-100% to provide
precise temperature control through the full range of ows. A Hi-Limit thermostat with automatic reset shall
be factory installed to disconnect each heating element in the event of an over-temperature condition. An
electronic digital display temperature controller shall be user adjustable in 1° increments in either °F or °C
and shall display ow rate, outlet temperature, inlet temperature and provide error indication. A turbine-type
ow meter shall be factory installed to provide precise temperature control for water ows as low as 0.2 GPM
up to a maximum ow of 8 GPM. Heaters that require greater than 0.2 GPM ow for actuation or heaters that
utilize on/off ow switch technology or restrict ow shall not be acceptable. (
Optional Specication: High
Flow Model MHX, provides up to 40 GPM ow with minimum actuation at 0.5 GPM ).
Warranty
Hubbell shall warranty all electrical components against defects in workmanship and material for a period of
one (1) year from date of start-up, and the heating chamber for ve (5) years from date of start-up, provided
that the unit is started within three (3) months of date of shipment and installed and operated within the scope
of the heater's design and operating capability. Labor is not covered under warranty. Each heater shall be
shipped with a complete set of installation and operating instructions including spare parts list and drawing.
All fabrication and assembly shall be performed in the U.S.A.
Options
In addition, the water heater shall be supplied with the following options:
Marine Products Division
Option
Option
Option
ISO 9001:2008
Committed to continuous improvements
Contin uing researc h resul ts in pro duct improvement; therefore these sp ecication s are
subject to chan ge without notice. For the most updated information, consult the factory.
The Electric Heater Company■ P.O. Box 288 ■ Stratford, CT 06615-0288