MARLO NXT2 Series User manual

MGT 240M–1200M
SYSTEM 7 – TWIN ALTERNATING
3” NXT2 SERIES
MODEL NO:
SERIAL NO:
DATE INSTALLED:
DEALER:
COMPLETE FOR FUTURE REFERENCE:
COMMERCIAL WATER CONDITIONER
INSTALLATION, OPERATION, AND MAINTENANCE MANUAL
Standard Image
Equipment appearance may differ.
Twin system shown with skid mount option.
8-634

MGT 240M–1200M NXT2 3” TWIN ALTERNATING
Inspection Requirement
Prior to Loading Media
1. Inspect condition of upper distributor piping. Verify
fittings are tight and positioned as shown.
2. Inspect condition of strainers, laterals and hub through
top or side access ports. Verify fittings are secured
to hub.
3. DO NOT load media if damaged components are
observed. Contact factory.
4. Installer is responsible for media loss into treated water
resulting from failure to report and repair damaged
components inside media tank prior to media loading.
5. INSTALLER WARNING:
Refer to installation instructions for media loading
procedure. Improper loading of media will damage
components inside media tank.
PRIOR TO
Media Loading
AFTER
Media Loading
SIDE
VIEW
Lateral
Hub
Distributor Tube
Media Tank
Softener/
Filter Media
Gravel
Media
TOP
VIEW
Media Tank
Lateral
Hub
5-272
IMPORTANT PLEASE READ:
• Warranty of this product extends to manufacturing defects.
• The information, specications and illustrations in this manual are based on the latest information
available at the time of printing. The manufacturer reserves the right to make changes at any time
without notice.
• This product should be installed by a plumbing professional on potable water systems only.
• This product must be installed in compliance with all local and state and municipal plumbing and
electrical codes. Permits may be required at the time of installation.

TABLE OF CONTENTS
SYSTEM INFORMATION
Product Warranty...........................................................................................................................................................1
General Arrangement Drawings ....................................................................................................................................2
Dimension Chart ...........................................................................................................................................................4
Speci ication Chart .......................................................................................................................................................5
INSTALLATION
General Information.......................................................................................................................................................6
Loading Softener ..........................................................................................................................................................7
Mounting Control Valve ................................................................................................................................................7
Brine Tank Installation .................................................................................................................................................. 8
Mounting Water Meter ................................................................................................................................................. 10
Network Communication Cables/Connections ............................................................................................................ 10
Power Supply Wiring ...................................................................................................................................................11
Connection Piping Installation .....................................................................................................................................11
OPERATION
Timer Display Features ...............................................................................................................................................12
System Operation........................................................................................................................................................13
Timer Operation...........................................................................................................................................................13
Start-Up Procedures....................................................................................................................................................15
User Mode Programming Flow Chart..........................................................................................................................16
Batch Size Calculation.................................................................................................................................................17
Diagnostic Mode Flow Chart .......................................................................................................................................18
Master Programming Flow Chart.................................................................................................................................19
Master Programming Guide ........................................................................................................................................21
Flow Diagrams.............................................................................................................................................................22
Wiring Diagram............................................................................................................................................................24
MAINTENANCE
Powerhead Assembly .................................................................................................................................................25
NXT2 Timer Assembly.................................................................................................................................................27
Control Valve Assembly...............................................................................................................................................28
Brine Injector Assemblies ...........................................................................................................................................30
Meters and Flow Sensors ...........................................................................................................................................34
Brine Tank Assemblies ...............................................................................................................................................37
Service Assemblies ....................................................................................................................................................41
Troubleshooting...........................................................................................................................................................42
MGT 240M–1200M NXT2 3” TWIN ALTERNATING

MGT 240M–1200M NXT2 3” TWIN ALTERNATING
SYSTEM INFORMATION
1
COMMERCIAL AND INDUSTRIAL PRODUCT WARRANTY
Manufacturer warrants all commercial and industrial water treatment products manufactured and/or distributed by it to
be free from defects in materials and workmanship for a period of one (1) year after installation or eighteen (18)
months from the date of shipment, whichever comes rst. The berglass mineral tank(s) alone have a warranty for a
period of ve (5) years from the date of shipment. If within that period any products shall be proven to Manufacturer’s
satisfaction to be defective, those products will be replaced or the price refunded at Manufacturer’s option.
Manufacturer’s obligations or nonperformance, defective, or any damage caused by its products or their use, and
buyer’s exclusive remedy therefore, shall be limited to product replacement or refund and shall be conditioned upon
Manufacturer’s receiving written notice together with a demand for such replacement or refund:
The foregoing warranty is exclusive and in lieu of all other expressed implied warranty (except of title) including but
not limited to implied warranty of merchantability and tness for particular purpose.
Manufacturer will not be subject to and disclaims the following:
1. Any other obligations or liabilities arising out of breach of contract or out of warranty.
2. Any obligations whatsoever arising from tort claims (including negligence and strict liability or arising under other
theories of law with respect to products sold or services rendered by Manufacturer or any undertakings, acts, or
omissions relating thereto.
3. All consequential, incidental, and contingent damages.
Labor charges, charge backs or handling charges are excluded from Manufacturer’s warranty provisions.
COMMERCIAL AND INDUSTRIAL WATER SOFTENER GUARANTEE
Under normal operating conditions:
1. The softener efuent shall be zero soft as determined by a soap test.
2. The loss of softening resin through attrition during the rst three (3) years shall not exceed 3% per year.
3. The softening resin shall not be washed out of the system during backwash.
4. The color and turbidity of the softener efuent shall not be greater than the incoming water.

MGT 240M–1200M NXT2 3” TWIN ALTERNATING
SYSTEM INFORMATION
2
5-232

MGT 240M–1200M NXT2 3” TWIN ALTERNATING
SYSTEM INFORMATION
3
FRONT VIEW
BACK VIEW
1 1
2 2
3 3
4 4
5 5
6 6
7 7
8 8
A A
B B C C
D D
DATE FRAC. DRN. APP'D.
_
DEC.
_
DRAWING NO.
SCALE
FILE ID.
SHEET
REV.
OF
MGT-600-3 TW-ALT SKID - PVC
GENERAL ARRANGEMENT
11
Anthony
2/18/2010 1
REVISIONS
NO. BY REMARKS
112/13/13 AJJG ADDED VACUUM RELIEF VALVES
DATE
RESIN TANK BRINE TANKRESIN TANK
AUTOMATIC BACKWASH
FLOW CONTROLLER
BY-PASS
VALVE
(NORMALLY
CLOSED)
3" RAW WATER INLET 30-100 PSIG
3" SOFT WATER
OUTLET
INLET ISOLATION
VALVE
OUTLET ISOLATION
VALVE
OVER FLOW TO DRAIN
NOTES: 1. OVERALL HEIGHT IS FOR REFFERENCE ONLY. ACTUAL
HEIGHT MAY VARY BASED ON TANK PROVIDED.
ALLOW 36" FOR
RESIN LOADING
WATER INLET
PRESSURE GAUGE
AND SAMPLE COCK
(TYP.)
WATER OUTLET
PRESSURE GAUGE AND SAMPLE COCK
(TYP.)

MGT 240M–1200M NXT2 3” TWIN ALTERNATING
SYSTEM INFORMATION
4
DIMENSION CHART
MODEL INLET SIZE
(Inches)
TANK SIZE LENGTH
(Inches)
WIDTH
(Inches)
HEIGHT*
(Inches)
SOFTENER
(Inches)
BRINE
(Inches)
240 3 24x72 24x50 89 24 95
300 3 24x72 24x50 89 24 95
450 3 30x72 30x50 115 30 93
600 3 36x72 39x60 129 39 94
750 3 42x72 39x60 140 42 113
900 3 42x72 42x60 143 42 113
1050 3 48x72 42x60 155 48 113
1200 3 48x72 42x60 155 48 113
*Leave a minimum 24 inch clearance to the height of the unit for loading media.
Dimensions are for general arrangement use only.

MGT 240M–1200M NXT2 3” TWIN ALTERNATING
SYSTEM INFORMATION
5
SPECIFICATION CHART
SYSTEM SIZE
MODEL 240 300 450 600 750 900 1200
VALVE SIZE (IN) 3333333
MAX CAPACITY (KILOGRAINS) 240 300 450 600 750 900 1,200
MIN CAPACITY (KILOGRAINS) 160 200 300 400 500 600 800
FLOWRATE (GPM)
CONTINUOUS FLOWRATE (GPM) 120 114 160 185 200 165 205
PEAK FLOWRATE (GPM) 170 150 213 250 268 225 275
BACKWASH & FAST FLUSH (GPM) 15 15 25 30 35 35 35
BRINE DRAW & RINSE (GPM) 3.2 3.2 3.5 4.5 6.5 6.5 10
BRINE TANK REFILL (GPM) 2 2 5 5 10 10 10
TIMER
SETTINGS
BACKWASH & FAST FLUSH (MIN) 10 10 10 10 10 10 10
BRINE DRAW & RINSE (MIN) 60 60 80 80 80 90 90
FAST FLUSH (MIN) 10 10 10 10 10 10 10
BRINE TANK REFILL (MIN) 20 25 15 20 13 15 20
SOFTENER
TANK
SIZE (IN) 24x72 24x72 30x72 36x72 42x72 42x72 48x72
GRAVEL (LBS) 120 120 225 400 400 650 1000
RESIN (FT3)8 10 15 20 25 30 40
FREEBOARD (IN) 30 21 22 23 23 15 15
BRINE SYSTEMS
EQUIPMENT
TANK SIZE 24x50 24x50 30x50 39x60 39x60 42x60 42x60
MAX SALT STORAGE (LBS) 550 450 640 1700 1700 2000 1700
INJECTOR CODE 4456778
INJECTOR COLOR GRN GRN RED WHT BLU BLU YEL
MAX
SALT DOSAGE- MAX (LBS) 120 150 225 300 375 450 600
REFILL TIME - MAX (MIN) 20 25 15 20 13 15 20
MIN
SALT DOSAGE- MIN (LBS) 48 60 90 120 150 180 240
REFILL TIME - MIN (MIN) 8 10 6 8 5 6 8
REGENERATION WASTE VOLUME (GAL) 520 544 860 1020 1210 1315 2100
NOTES:
1. FLOW RATES
Continuous: pressure loss does not exceed 15 psig.
Peak: pressure loss does not exceed 25 psig
Backwash & Flush: maximum flow to drain
Brine & Rinse: Injector flow to drain
Brine Tank Refill: flow to refill Brine Tank
2. SOFTENER TANK
Freeboard: distance in inches from surface of resin to top sealing flange of tank
3. SALT DOSAGE
Maximum 15 lbs./cu.ft. - regeneration efficiency: 2,000 grains/pound of salt
(factory setting)
Maximum 6 lbs./cu.ft. - regeneration efficiency: 3,000 grains/pound of salt
4. REGENERATION WASTE VOLUME - Total gallons water discharged per
regeneration
5. OPERATING LIMITS:
Minimum operating pressure is 30 psi.
Maximum operating pressure is 120 psi.
Standard units are designed to soften unheated water within the range of
35-100°F.
6. POWER
Power requirements are 120 Volt, 60 Hertz, Single Phase, 2 amps
noninterrupted.
7. SALT
Salt specifications are pelletized or solar salt, 99% pure, containing
less than 1% insolubles (see Brine Tank Installation on page 8)

MGT 240M–1200M NXT2 3” TWIN ALTERNATING
INSTALLATION
6
INSTALLATION INSTRUCTIONS WATER SOFTENERS
GENERAL INFORMATION
1. Operating pressure range is 30-100 psi. If pressures over 100 psi are encountered, a regulator must be installed.
NOTE: The control valve will not operate correctly if feeding into an atmospheric tank. A pressure control device
must be added to the outlet to maintain the minimum pressure.
2. Power requirements are shown on inside cover of the control valve. You can also tell by wire color on the motor.
Black wires are 115 volt. Yellow wires are 220 volt. Blue wires are 24 volt.
3. Standard units are designed to soften unheated water not to exceed 100F. Special valve assemblies are available
to handle heated water supplies exceeding 100 F. Consult factory if applicable.
4. Each softener tank is shipped with distributor manifold and control valve preassembled. Take care when uncrating
and erecting so that no items are damaged.
5. The distributor assembly has been shipped inside the berglass mineral tank. Check to make sure that there is no
damage to the riser pipe, baskets, laterals or hub (if applicable).
NOTE: A prelter should be used on installations in which free solids are present
LOCATE SOFTENER
1. Select a location that is accessible and near a oor drain that has adequate carrying capacity to handle the
softener backwash ow (see specication table for ow rate). Allow a minimum of 24” above the tank for
loading media.
2. Erect the softener tank(s) on a concrete or other rm foundation and level.
3. Position the brine tank according to the illustration and supplementary brine tank information. Keep the brine tank
as close as possible to the softener tank(s).
Note: The distance between the softener and brine tanks will affect the brine injector performance, as the distance
increases the injector performance decreases. This may cause an inadequate regeneration. Maximum
recommended distance is 5 ft.
4. A grounded electric receptacle is required for the control valves.

MGT 240M–1200M NXT2 3” TWIN ALTERNATING
INSTALLATION
7
LOAD SOFTENER TANK
IMPORTANT: Be sure to visually inspect the lower laterals prior to loading
the media. Check to make sure each lateral is rmly threaded into the hub
1. Fill tank(s) approximately 1/3 full of water using a hose, bucket, etc. Plug the
PVC distributor manifold pipe using a plastic cap, cork, rag, etc. NO gravel or
resin should go into this distributor manifold pipe.
2. Verify the distributor manifold is center in the tank with the distributor resting
on the bottom of the tank. Verify the riser pipe is still plugged.
NOTE: Reference the specication table in the front of this manual for the
correct quantities of gravel and resin. Note that these quantities are for each
tank. Make sure you have the required amounts on site before you begin.
3. With care not to damage any lateral, pour in the gravel provided for each
tank through the top opening in the tank and level out evenly. This will cover
the distributor assembly.
NOTE: Wetting the gravel in the bags before loading will eliminate the normal
amount of dust.
4. When gravel is loaded and leveling is completed, proceed as follows:
5. With the distributor riser pipe still plugged, add the proper amount of resin
supplied for each tank through the top opening in the tank.
Caution: The softener resin is very slippery. Take care when stepping on any
pilled resin. Remove spilled resin from standing immediately.
6. When loading is complete, remove plastic cap, cork, or rag that was used to plug the distributor riser pipe. Be
careful not to let any foreign debris fall into the pipe. The result could be damage to system.
7. Repeat instruction steps 1-6 for each softener tank (if applicable).
MOUNT CONTROL VALVE ASSEMBLY
1. Verify that the distributor riser pipe is not plugged.
2. Lubricate the distributor o-ring on the bottom of the control valve with silicone.
3. Insert disperser into base of control valve. The base has a groove machined
into the inside of the anged part of the base to allow for the installation of
this disperser.
4. Place the tank o-ring and ange ring on the top of the tank. Line up the
bolt holes. Then place the valve o-ring on the ange ring.
5. Place the control valve onto the ange ring making sure the distributor riser
pipe slides easily through the distributor o’ring. Care must be taken not to
“nick” this o’ring as hard water leakage could result. Turn the control to align it
with the front of the tank.
6. Align the segmented rings with the holes in the ange ring and tank and use
the included bolts, washers, and nuts to secure the valve to the tank. Tighten
down the control valve to ensure positive o’ring seal at top of tank.
7. Repeat instruction steps 1-5 for each softener tank (if applicable)