Danfoss MT User manual

1FRCC.EI.002.A1.02 © Danfoss Commercial Compressors 04/08
The compressor must only be
used for its designed purpose(s) and
within its scope of application (refer
to «operating limits»).
Consult Application guidelines and da-
tasheet available from cc.danfoss.com
The compressor is delivered under
nitrogen gas pressure (between 0.3
and 0.7 bar) and hence cannot be
connected as is; refer to the «as-
sembly» section for further details.
Under all circumstances, the
EN378 (or other applicable local safety
regulation) requirements must be
fulfilled.
The compressor must be handled
with caution in the vertical posi-
tion (maximum offset from the
vertical : 15°)
Operating limits MT MTZ MTZ MTZ NTZ
R22 R407C R134a R404A / R507A
High side pressure range bar (g) 10,9 - 27,7 12,5 - 29,4 7,9 - 22,6 13,2 - 27,7 13,2 - 27,7
Low side pressure range bar (g) 1,0 - 7,0 1,4 - 6,6 0,6 - 4,7 1,0 - 7,2 0,1 - 3,3
Discharge temperature must be kept lower than 130°C
Housing
Service
Pressure
Lubricant
Supply Voltage
Maximum current
Starting current
Model
Number
Serial
Number
1" : 80 Nm
1"1/4 : 90 Nm
1"3/4 : 110 Nm
Installation and servicing of the compressor by qualified personnel only. Follow these instructions and sound refrigeration engineering
practice relating to installation, commissioning, maintenance and service.
HM8-40
15 Nm
230 V
A + C
Thermostat
C
SR
IOL
1 PSC 1 CSR 3
230 V
Thermostat
BµF
Start Relay
5
2
1
15 kΩ -1 w
C
SR
IOL
A + C
C
R
S
C
R
S
Never operate compressors without terminal cover fitted
15 Nm
HM12-50
∼∼ ∼
INSTRUCTIONS
MT / MTZ / NTZ COMPRESSORS

1 - Introduction
These instructions pertain to the Maneurop® MT,
MTZ & NTZ compressors used for refrigeration
systems. They provide necessary information re-
garding safety and proper usage of this product.
2 – Handling and storage
 • Handle the compressor with care. Use the
dedicated handles in the packaging. Use the
compressor lifting lug and use appropriate and
safe lifting equipment.
 • Store and transport the compressor in an
upright position.
 • Store the compressor between -35°C and
50°C.
 • Don’t expose the compressor and the packa-
ging to rain or corrosive atmosphere.
3 – Safety measures before assembly
Never use the compressor in a flammable at-
mosphere.
 • Thecompressorambienttemperaturemaynot
exceed 50°C during off-cycle.
 • Mountthecompressoronahorizontalatsur-
face with less than 3° slope.
 • Verifythatthepowersupplycorrespondsto
the compressor motor characteristics (see
nameplate).
 • When installing MTZ or NTZ, use equipment
specifically reserved for HFC refrigerants which
was never used for CFC refrigerants.
 • Usecleananddehydratedrefrigeration-grade
coppertubesandsilveralloybrazingmaterial.
 • Usecleananddehydratedsystemcomponents.
 • Thepipingconnectedtothecompressormustbe
flexible in 3 dimensions to dampen vibrations.
4 - Assembly
 • Slowly release the nitrogen holding charge
through the schrader port.
 • Remove the gaskets when brazing rotolock
connectors.
 • Alwaysusenewgasketsforassembly.
 • Connectthecompressortothesystemassoon
as possible to avoid oil contamination from
ambient moisture.
 • Avoidmaterialenteringintothesystemwhile
cutting tubes. Never drill holes where burrs
cannot be removed.
 • Braze with great care using state-of-the-art
technique and vent piping with nitrogen gas
flow.
 • Connect the required safety and control de-
vices.Whentheschraderportisusedforthis,
remove the internal valve.
5 – Leak detection
Neverpressurizethecircuitwithoxygenordry
air. This could cause fire or explosion.
 • Donotusedyeforleakdetection.
 • Performaleakdetectiontestonthecomplete
system.
 • Thelowsidetestpressuremustnotexceed25
bar.
 • Whenaleakisdiscovered,repairtheleakand
repeat the leak detection.
6 – Vacuum dehydration
 • Never use the compressor to evacuate the
system.
 • ConnectavacuumpumptoboththeLP&HP
sides.
 • Evacuatethesystem toa pressureof 500µm
Hg (0.67 mbar) absolute.
 • Donotuseamegohmmeternorapplypower
to the compressor while it is under vacuum as
this may cause internal damage.
7 – Electrical connections
 • Switchoandisolatethemainpowersupply.
Seeoverleafforwiringdetails.
 • The compressor is protected against excess
current and temperature by an internal over-
load protector. Follow local regulations regar-
ding power line protection. The compressor
must be connected to earth.
 • Allelectricalcomponentsmustbeselectedasper
local standards and compressor requirements.
8 – Filling the system
 • Keepthecompressorswitchedo.
 • Fill the refrigerant in liquid phase into the
condenser or liquid receiver. The charge must
be as close as possible to the nominal system
charge to avoid low pressure operation and ex-
cessive superheat.
 • Keepthe refrigerantchargebelow 2.5kgper
compressor cylinder if possible. Above this
limit; protect the compressor against liquid
flood-back with a pump-down cycle or suction
line accumulator.
 • Never leave the lling cylinder connected to
the circuit to avoid overfilling.
9 – Verification before commissioning
Use safety devices such as safety pressure
switch and mechanical relief valve in compliance
with both generally and locally applicable regu-
lations and safety standards. Ensure that they are
operational and properly set.
Check that the settings of high-pressure swit-
chesandreliefvalvesdon’texceedthemaximum
service pressure of any system component.
 • A low-pressure switch is recommended to
avoid vacuum operation. Minimum setting 0.1
bar.
 • Verify that all electrical connections are pro-
perly fastened and in compliance with local
regulations.
 • Whenacrankcaseheaterisrequired,itmustbe
energizedatleast12hoursbeforeinitialstart-
up and start-up after prolonged shutdown.
10 – Start-up
 • All service valves must be in the open posi-
tion.
 • BalancetheHP/LPpressure.
 • Energizethecompressor.Itmuststartpromptly.
Ifitdoesnot,switchitoimmediately.Possible
single phase miswiring can cause burn-out
within seconds.
 • Ifthecompressordoesnotstart,checkwiring
conformity and voltage on terminals.
 • If the internal overload protector trips out, it
must cool down to 60°C to reset. Depending
on ambient temperature, this may take up to
several hours.
11 – Check with running compressor
 • Checkcurrentdrawandvoltage.
 • Check suction superheat to reduce risk of
slugging.
 • Whenasightglassisprovidedobservetheoil
level at start and during operation to confirm
that the oil level remains visible.
 • Respecttheoperatinglimitsasprintedoverleaf.
 • Checkalltubesforabnormalvibration.Move-
ments in excess of 1.5 mm require corrective
measures such as tube brackets.
 • When needed, additional refrigerant in the
liquid phase may be added in the low-pressure
side as far as possible from the compressor.
The compressor must be operating during this
process.
 • Donotoverchargethesystem.
 • Neverreleaserefrigeranttotheatmosphere.
 • Before leaving the installation site, carry out
a general installation inspection regarding
cleanliness, noise and leak detection.
 • Recordtypeandamountofrefrigerantcharge
as well as operating conditions as a reference
for future inspections.
12 - Maintenance
Internal pressure and surface temperature
are dangerous and may cause permanent injury.
Maintenance operators and installers require
appropriate skills and tools. Tubing temperature
may exceed 100°C and can cause severe burns.
Ensure that periodic service inspections to
ensure system reliability and as required by local
regulations are performed.
To prevent system related compressor problems,
following periodic maintenance is recommended:
 • Verify thatsafetydevices areoperational and
properly set.
 • Ensurethatthesystemisleaktight.
 • Checkthecompressorcurrentdraw.
 • Conrmthatthesystemisoperatinginaway
consistent with previous maintenance records
and ambient conditions.
 • Check that all electrical connections are still
adequately fastened.
 • Keepthecompressorcleanandverifytheab-
sence of rust and oxidation on the compressor
shell, tubes and electrical connections.
13 - Warranty
Always transmit the model number and serial
number with any claim filed regarding this pro-
duct.
The product warranty may be void in following
cases:
 • Absenceofnameplate.
 • External modications; in particular, drilling,
welding, broken feet and shock marks.
 • Compressoropenedorreturnedunsealed.
 • Rust, water or leak detection dye inside the
compressor.
 • Useofarefrigerantorlubricantnotapproved
by Danfoss.
 • Anydeviationfromrecommendedinstructions
pertaining to installation, application or main-
tenance.
 • Useinmobileapplications.
 • Useinexplosiveatmosphericenvironment.
 • Nomodelnumberorserialnumbertransmitted
with the warranty claim.
14 – Disposal
Danfoss recommends that compressors
and compressor oil should be recycled by
a suitable company.
2FRCC.EI.002.A1.02 © Danfoss Commercial Compressors 04/08
Instructions