Matsui DMZ-80, DMZ-120, DMZ-40, DMZ-170, DMZ-240 Service Manual

SERVICE MANUAL

MAINTENANCE AND TROUBLESHOOTING

GUIDE

FOR MATSUI DMZ DRYERS

Phone [phone] Fax [phone] www.matsuiamerica.com

INTRODUCTION 2
NOMENCLATURE 2-3
DAILY MAINTENANCE SCHEDULE 4
MONTHLY MAINTENANCE SCHEDULE 4
6 MONTH MAINTENANCE SCHEDULE 4
MAINTENANCE DESCRIPTIONS AND DIRECTIONS 5-12
ALARMS 13-18
TROUBLESHOOTING 19-22
FREQUENTLY ASKED SERVICE QUESTIONS 23-25
COMMON SPARE PARTS 26

ITEM: PAGE:

INTRODUCTION

Matsui’s DMZ Desiccant Dryer is a high-performance machine designed for fast,
low dew point drying of plastic pellets, easy maintenance and long life. As with
any machine, some basic maintenance steps must be completed regularly to
ensure proper operation and the quick, complete drying the DMZ is capable of.
This guide contains the recommended maintenance intervals and procedures for
trouble-free operation. Also included is a section on basic troubleshooting. In the
event that a dryer’s performance falters, use this guide to help find the possible
cause, as well as the remedy to keep your DMZ running properly and at peak
performance.

NOMENCLATURE

Desiccant Rotor: The desiccant rotor is the heart of the DMZ dryer. This
revolutionary design allows for constant and steady absorption and regeneration
cycles. The result is a steady, constant low dew point of -40°F or lower. The
desiccant rotor is turned through the various cycles at the rate of 3 revolutions
per hour. If, for whatever reason, this rotor is not turning, absorption and
regeneration will not occur, preventing moisture removal from the material.

Regeneration: Regeneration, as it is referred to in this guide, is the process of
drying the moisture absorbed by the desiccant rotor. This involves the use of a
blower with an intake filter, a heater and heater tank, hoses and an exhaust port.
Ambient air is drawn in through the regeneration filter by the regeneration blower
and blown over the regeneration heater where it is heated to 446°F (230° C). The
heated air is then blown over the saturated desiccant rotor to burn off the
moisture. Heat and airflow are the most important aspects of regeneration. If
either is not correct, proper drying will not occur. A clean regeneration filter and
properly working electrical components are mandatory.

Process: Process, as referred to in this guide, is the heated air that flows over
the plastic pellets inside the drying hopper. This involves a process filter, process
blower and process heater, to produce hot air to blow over the resin in the
hopper. Because hot air gathers and holds more moisture then cold air, it is
important to have the process side of the dryer working correctly. Heat and
airflow are the most important aspects of removing moisture from the plastic
pellets. If there is proper heat, but not enough airflow to carry the moist air out of
the hopper to the desiccant rotor, poor drying will occur. Likewise, if there is
proper airflow, but the air is not hot enough to gather the moisture, inadequate
drying will occur. A clean process filter and properly working electrical
components are mandatory.

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Aftercooler: Inside each DMZ there is an aftercooler for the process air. The
aftercooler serves several purposes. First and foremost, it protects the desiccant
rotor by catching any small fines that may get past the process filter and build up
in the rotor. It also condenses any gases that may be given off during the heating
of the plastic pellets. The Aftercooler begins to cool the moist process air before
it goes through the desiccant rotor, to help the air “give up” the moisture to the
desiccant. Inadequate water flow to the aftercooler may result in a higher dew
point and poor drying conditions. In addition, it cools down the hot air moving
through the process blower, which will help increase the life-span of bearings,
motor, etc.

Thermocouple: The thermocouple, simply stated acts like a thermometer and
senses the temperature of the air flowing through either the regeneration heater,
or the process heater. The thermocouple reports the temperature to the unit
controller. If the Process temp is set for 200° F, and the thermocouple is either
misadjusted or broken, two results can occur: First, if the temperature in the
hopper is too low, moisture will not be removed from the plastic pellets. Likewise,
if the temperature is too high, a melt down inside the hopper can occur. A
properly adjusted thermocouple is important to insure proper drying.

Magnetic Contactors: magnetic contactors are the “switches” that turn the
heaters and blowers on and off, following the commands of the temperature
controller. These contactors are generally good for 1 million on / off cycles. This
means if a dryer is running 24 hours 7 days a week, the heater contactors will
last about 9 months. The blower contactors last considerably longer, as once the
blower is on, the contactor is not cycling on and off. The constant on / off action
is what wears out a contactor. Watching the heater contactors is especially
important because if one or more legs of the contactors burn out, eventually, the
corresponding heater will burn out. Contactors are cheaper than heaters.

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DAILY MAINTENANCE

MAINTENANCE ITEM: PROCEDURE:
Regeneration filter Blow out with compressed air
Process filter Blow out with compressed air
Regeneration Temperature Confirm set point being reached
Process Temperature Confirm set point being reached
Thermocouple on Drying Hopper Check for damage, replace if necessary
Drying Hoses Check for wear, replace if necessary

MONTHLY MAINTENANCE

MAINTENANCE ITEM: PROCEDURE:
Regeneration filter Blow out with compressed air
Process filter Blow out with compressed air
Regeneration Temperature Confirm set point being reached
Process Temperature Confirm set point being reached
Thermocouple on Drying Hopper Check for damage, replace if necessary
Drying Hoses Check for wear, replace if necessary
Aftercooler Water Supply Check that water valve is open
Magnetic Heater Contactors Check resistance
Regeneration Heater Ohms check
Process Heater Ohms check
Desiccant Rotor Turning or indexing properly

6 MONTH MAINTENANCE

MAINTENANCE ITEM: PROCEDURE:
Regeneration Filter Replace
Process Filter Replace
Regeneration Temperature Confirm set point being reached
Process Temperature Confirm set point being reached
Thermocouple on Drying Hopper Check for damage, replace if necessary
Drying Hoses Check for wear, replace if necessary
Aftercooler Water Supply Clean strainer
Magnetic Heater Contactors Check resistance, replace if necessary
Magnetic Blower Contactors Check resistance, replace if necessary
Regeneration Heater Ohms check
Process Heater Ohms check
Desiccant Rotor Turning or indexing properly
Cabinet interior Vacuum or blow out with compressed air
Nuts and bolts Check for loose nuts and bolts throughout

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MAINTENANCE DESCRIPTIONS AND DIRECTIONS

Regeneration Filter: In all models, the regeneration filter is mounted directly on
the regeneration blower. This filter cleans the air flowing over the regeneration
heater and through the desiccant rotor.
sure the dryer is shut off and the blowers stopped.
On the
hole at the bottom. This filter, since it is low to the ground, gets very dirty very
fast! Remove this filter by unscrewing the hold down wing nut and removing the
nut and washer.
On
square hole at the top of the rear panel. The filter simply unscrews from the
blower and removed through the hole.
On DMZ-170 and 240 models, the filter is accessed through a flip-down
panel at the top rear of the dryer, Remove the two wing screws holding the panel
shut. With the door panel open, remove the wing nut and washer holding the
regeneration filter in place.
inside out. The filter should be changed every 6 months or sooner under servere
conditions. The regeneration exhaust should blow as hard with a clean filter

as it does with no filter. If you blow out the filter and the airflow from the
regeneration exhaust diminishes considerable when you re-install the filter,
install a new filter! In all cases, installation is in reverse order of removal.

Process Filter: On DMZ 40-240, the process filter is located on the back middle
of the dryer.
both blowers have stopped. This is important to keep foreign matter out of the
desiccant rotor. Remove the knurled knob and washer holding the round cover in
place. With the cover off, remove the wing nut and rubber washer holding the
filter in place.
should be changed every 6 months or sooner under severe conditions. If the

filter has been blown out and the inside does not look white anymore,
install a new filter! Replace the filter in the reverse order of removal, being sure

to install the rubber washer rubber side against the filter.

DMZ-40 DMZ-80 / 120 DMZ-170 / 240

DMZ-40 model, this filter is accessed on the back panel, through a

DMZ-80 and 120 models, the regeneration filter is accessed through a

Using compressed air, blow out the filter from the

REGENERATION FILTER LOCATIONS

To clean or change this filter, first shut down the dryer and be sure

Using compressed air, blow out the filter from the inside. The filter

To clean or change this filter, first, make

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Regeneration Temperature: The regeneration temperature is factory set at

446°F (230°C). This is the optimum temperature for removing moisture from the
desiccant rotor during the regeneration cycle. This temperature can be checked
by pressing the “PV” button on the face of the controller until the L.E.D. indicator
is under the word “REGEN” and 446° reads in the “PV” window. A regeneration
temperature of less that 410°F (210°C) is indicative of a problem with the
regeneration system.

Process temperature: Simply stated, if the process, or drying temperature in the

“PV” window is more than a few degrees off from the temperature entered in the
“SV” window, after an hour of running, there is probably a problem on the drying
side of the DMZ. Remember though, the minimum guaranteed temperature for a
DMZ is 130°F (54°C), so it may not go lower than that.

Thermocouple on Drying Hopper: The thermocouple on the drying hopper

should be checked for damage and proper adjustment regularly. The end tip
should be dead center in the middle of the heater box tube. This should be
factory set, however check to make sure the nut is tight and the thermocouple
can’t move up or down. If the thermocouple is severely bent or broken, replace it!
Inside the thermocouple there are two very small and fragile wires that can easily
be damaged if the thermocouple is smashed or bent. If these wires are damaged,
or the thermocouple is misadjusted, the temperature controller may inaccurately
sense the hopper temperature. This can cause poor drying, or in the worst case
a material meltdown in the hopper.

THERMOCOUPLE ADJUSTMENT

DAMAGED CORRECTMISADJUSTED

Drying Hoses: The drying hoses, or the orange Hoses, should be checked

regularly for cuts, abrasions, kinks or other damage that would impede maximum
air flow. If a hose is cut, outside air can be brought into the machine thus
reducing the ability of the dryer to create a dry material, Likewise, is a hose is
kinked or crushed, airflow over the resin pellets may be impeded, slowing the
time it takes to dry the material. Damaged hoses should be replaced
immediately.

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Aftercooler Water Supply: Check to make sure that water is flowing to the

aftercooler. Make sure the valve is open and clean the strainer at least twice a
year. To clean the strainer, shut off the water valve, and remove the strainer nut
at the bottom of the strainer. Remove the strainer and clean it of debris and any
corrosion. Replace the strainer and tighten the nut.

STRAINER MAINTENANCE

REMOVE AND CLEAN STRAINER

Magnetic Heater Contactors: The heater contactors should be checked on a

monthly basis to ensure proper operation. Typically there are two Heater
contactors, although some high heat models may have three or four. There are
two ways to check a contactor. In either case, you will need a Multi-Meter to
properly check operation.

VOLTAGE CHECK:

Electrical maintenance should only be performed by individuals with
proper electrical knowledge and training

The first check, the voltage check, can be done with the machine running.

Always use extreme caution when working on and around the high voltage
inside the electrical cabinet.

1) Set the Multi-meter to the proper AC voltage setting that corresponds to
the voltage rating of your machine.

2) Confirm that the proper voltage is being supplied to the “line” side of the
contactor by checking the “line” side leads horizontally, between each pair
of “line “ leads, (L1&L2, L1&L3 and L2&L3). This voltage should be the
same as the plant voltage. (See fig. 1)

3) Next, repeat this process on the “load” side leads of the contactor. Keep
in mind you will only get a voltage reading when the contactor is active,
(contacts pulled in). The voltage should be the same across the “load”
side (T1&T2, T1&T3 and T2&T3) as it is on the “line” side. (See fig 2) If
one or more of the leads has substantially lower or no voltage, this is
indicative of a defective contactor. Be sure to shut off the power at the

breaker or buildings disconnect before replacing the contactor.

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Magnetic Heater Contactors Cont.

CHECKING INPUT VOLTAGE

RESISTANCE CHECK:

The second check, the resistance check must be done with the power to the
machine off. Be sure to shut off the power at the breaker or buildings

disconnect before proceeding.

1) Set the Multi-meter to the Ohms setting. The Ohms setting may be
labeled Ω. Once again, be sure the power to the dryer if off.

2) Place one of the meter probes on a “line” side terminal and the other to
the corresponding “load” side terminal, for example L1&T1, L2&T2,
L3&T3. (See fig 1.)

3) With the probes in place, manually press the actuator on the center
face of the contactor until the contactor closes and a reading appears
on the meter. Repeat across all three phases. (See fig. 2.)

4) The measured value should be between 0.00-0.03 Ohms. A greater
value is indicative of a defective contactor, which should be replaced.

Be sure to shut off the power at the breaker or buildings
disconnect before replacing the contactor.

METER PROBES CONTACTOR CLOSED CORRECT RANGE

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Magnetic Blower Contactors: Follow the same directions as the magnetic

heater contactors.

Regeneration Heater: The regeneration heater should be checked for proper

resistance regularly to confirm it is working properly and ensure proper desiccant
rotor operation. Like any mechanical part, heaters wear over out over time. Worn
or defective magnetic contactors can also damage a heater. Checking heaters,
like checking contactor resistance, is done with the power off. You will need a
Multi-meter to complete this test. Be sure to shut off the power at the breaker

or buildings disconnect before proceeding.

1) Set the Multi-meter to the Ohms setting. The Ohms setting may be
labeled Ω. Once again, be sure the power to the dryer if off.

2) Measure Ohms at the load side of the contactor (heater wire terminals)
between all three leads in each combination (T1&T2, T1&T3 and
T2&T3). Every combination should have the same Ohm reading, give
or take 3 or 4 Ohms. If the heater is aging equally across all three
elements, the Ohms values should be similar.

3) To calculate exact values, Check the chart on page 10, or use the
following formula to calculate the exact values:

R = 2xVxV

W

R = Resistance
V = Voltage
W = Watts

Example: 2x230x230

1.5kw (1500)*

* Be sure to change Kilo value to its actual value. (2.4kw =2400 w)

In this example, resistance is 70.5 Ohms
So, in this case, you should have 70.5 Ohms across all three heater lines.

Process Heater: Follow the same directions as the regeneration heater.

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Heaters cont.

EXAMPLE OF HEATER RESISTANCE

HOPPER HEATER RESISTANCE CHART (ohms)

HOPPER HEATER

230V 460V

HD-15R 1.5 kW 70.5 Ω 282.1 Ω
HD-25R 2.4 kW 44.1 Ω 176.3 Ω
HD-50R 2.4 kW 44.1 Ω 176.3 Ω
HD-75R 3.3 kW 32.1 Ω 128.2 Ω
HD-100R 3.3 kW 32.1 Ω 128.2 Ω
HD-150R 4.0 kW 26.5 Ω 105.8 Ω
HD-200R 4.0 kW 26.5 Ω 105.8 Ω
HD-250R 3.0 kW 35.3 Ω 141.1 Ω
Dual Element 3.0 kW 35.3 Ω 141.1 Ω
HD-300R 3.0 kW 35.3 Ω 141.1 Ω
Dual Element 3.0 kW 35.3 Ω 141.1 Ω
HD-15RDH 2.1 kW 50.4 Ω 201.5 Ω
HD-25RDH 4.0 kW 26.5 Ω 105.8 Ω
HD-50RDH 4.0 kW 26.5 Ω 105.8 Ω
HD-75RDH 6.0 kW 17.6 Ω 70.5 Ω
HD-100RDH 6.0 kW 17.6 Ω 70.5 Ω
HD-150RDH 3.9 kW 26.6 Ω 108.5 Ω
Dual Element 3.9 kW 26.6 Ω 108.5 Ω
HD-200RDH 3.9 kW 26.6 Ω 108.5 Ω
Dual Element 3.9 kW 26.6 Ω 108.5 Ω
HD-250RDH 6.2 kW 17.1 Ω 68.3 Ω
Dual Element 6.2 kW 17.1 Ω 68.3 Ω
HD-300RDH 6.2 kW 17.1 Ω 68.3 Ω
Dual Element 6.2 kW 17.1 Ω 68.3 Ω

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