MLZ Compressors
Specifications
- Models: MLZ 015-026, MLZ 030-045, MLZ 048, MLZ 058-076
- Brazed connection size:
- Suction: 3/4, Discharge: 1/2
- Suction: 7/8, Discharge: 1/2
- Suction: 7/8, Discharge: 3/4
- Suction: 1 1/8, Discharge: 7/8
- Rotolock connection size:
- Suction: 1 1/4, Discharge: 1
- Suction: 1 1/4, Discharge: 1
- Suction: 1 1/4, Discharge: 1 1/4
- Suction: 1 3/4, Discharge: 1 1/4
- Refrigerant Charge Limit:
- MLZ015-019-021-026: 3.6 kg / 8 lb
- MLZ030-038-045-048: 5.4 kg / 12 lb
- MLZ058-066-076: 7.2 kg / 16 lb
Product Usage Instructions
Installation and Servicing
Installation and servicing should be carried out by qualified
personnel only. Follow sound refrigeration engineering practices
related to installation, commissioning, maintenance, and
service.
Safety Precautions
Never operate the compressor without the terminal box cover in
place and secured. Use safety devices such as safety pressure
switches and mechanical relief valves in compliance with
regulations.
Handling and Maintenance
Do not disassemble bolts, plugs, or fittings unless all pressure
has been relieved from the compressor. Do not operate the
compressor under vacuum as it may cause internal damage.
Electrical Connections
Follow the specified electrical connections using quick connect
spade terminals for T and P terminal box types and ring connect
screw terminals for Q and C terminal box types.
FAQ
Q: What is the recommended refrigerant for the MLZ scroll
compressors?
A: The approved refrigerants are R407A, R134a, R407F,
R448A/R449A, R404A/R507, R22, R452A, and R513A.
Q: What are the operating limits for the compressor?
A: The operating limits vary based on the refrigerant being
used. Refer to the provided chart for specific operating
limits.
Instructions
Danfoss scroll compressors MLZ
A B C
D E
A: Model number
B: Serial Number
C: Technical number
F
D: Internal protection
G
E: Manufacturing year
H
F: Supply voltage range
I
G: Locked rotor current
Maximum operating current
H: Lubricant type and nominal charge
I: Approved Refrigerant
Operating limits
Cond. temp. (°C)
Cond. temp. (°C)
MLZ – R407A
75
70 65
60 55
50
SH 10K
45
40
RGT 20°C
35
30
MLZ076
25
20 15
10
5
-35
-30
-25
-20
-15
-10
-5
0
Evap. temp. (°C)
5
10
15
20
Cond. temp. (°C)
MLZ – R134a
75
70 65
60
55 SH 11K
50
45
40
35 30
25
20 15
10
5
-35
-30
-25
-20
-15
-10
-5
0
Evap. temp. (°C)
5
10
15
20
Cond. temp. (°C)
MLZ – R407F
75
70 65
60 55
50
45
SH 10K
40 RGT 20°C
35 MLZ076
30
25
20 15
10
5
-35
-30
-25
-20
-15
-10
-5
0
Evap. temp. (°C)
5
10
15
20
Cond. temp. (°C)
MLZ – R448A/R449A
75
70 65
60 55
50
45
SH 10K
40
RGT 20°C
35 30
25
20 15
10
5
-35
-30
-25
-20
-15
-10
-5
0
Evap. temp. (°C)
5
10
15
20
MLZ – R404A/R507
75
70 65
60
55 SH 10K
50
45 RGT 20°C
40
35 30
25
20 15
10
5
-35
-30
-25
-20
-15
-10
-5
0
Evap. temp. (°C)
5
10
15
20
Cond. temp. (°C)
75 70 65 60 55 50 45 40 35 30 25 20 15 10 5
-35
SH 10K
-30
-25
MLZ – R22
RGT 20°C
-20
-15
-10
-5
0
Evap. temp. (°C)
5
10
15
20
Cond. temp. (°C)
MLZ – R452A
75
70 65
60 55
50
SH 10K
45
40 RGT 20°C
35
30
25
20 15
10
5
-35
-30
-25
-20
-15
-10
-5
0
Evap. temp. (°C)
5
10
15
20
Cond. temp. (°C)
MLZ – R513A
75
70 65
60 SH 10K
55 RGT 20°C
50
45
40
35 30
25
20 15
10
5
-35
-30
-25
-20
-15
-10
-5
0
Evap. temp. (°C)
5
10
15
20
Single phase
N
L
Thermostat
Run capacitor
PSC wiring
C IOL
S
R
N
L
Thermostat
Run capacitor
Start Relay 5
2 1
CSR wiring
C
S
R
Start capacitor
15 k -1 w
Models
MLZ 015-026
MLZ 030-045
MLZ 048 MLZ 058-076
Brazed connection size
Suction 3/4″ Discharge 1/2″ Suction 7/8″ Discharge 1/2″ Suction 7/8″ Discharge 3/4″ Suction 1″1/8 Discharge 7/8″
Rotolock connection size Suction 1″1/4
Discharge 1″ Suct. 1″1/4 Discharge 1″ Suction 1″1/4 Discharge 1″ 1/4 Suction 1″3/4 Discharge 1″1/4
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.
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 datasheet available from cc.danfoss.com
Never operate compressor without terminal box cover in place and secured.
The compressor is delivered under nitrogen gas pressure (between 0.3 and 0.4 bar / 4 and 6 psi). Do not disassemble bolts, plugs, fittings, etc… unless all pressure has been relieved from the compressor.
Under all circumstances, the EN378 (or other applicable local safety regulation) requirements must be fulfilled. Wear protective goggles and work gloves. The compressor must be handled with caution in the vertical position (maximum offset from the vertical : 15°).
Electrical connections
C
push
T
S T
R T
push
Quick connect spade terminals T and P terminal box type
© Danfoss | DCS (CC) | 2018.06
Ring connect screw terminals Q and C terminal box type
push
8510284P01C – FRCC.PI.048.A3.02 | 1
1 Introduction
These instructions pertain to the MLZ scroll compressors used for refrigeration systems. They provide necessary information regarding 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 70°C / -31°F and 158°F.
· Don’t expose the compressor and the packaging to rain or corrosive atmosphere.
3 Safety measures before assembly
Never use the compressor in a flammable atmosphere. · Mount the compressor on a horizontal flat sur-
face with less than 7° slope. · Verify that the power supply corresponds to the com-
pressor motor characteristics (see nameplate). · When installing a compressor for R404A, R507
R407A, R407F, R448A/R449A, R513A, R452A or R134a, use equipment specifically reserved for HFC refrigerants which was never used for CFC or HCFC 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. · The compressor must always be mounted with the rubber grommets supplied with the compressor.
4 Assembly
· Slowly release the nitrogen holding charge through discharge and suction ports.
· 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 devices. When the schrader port, if any, 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 leak detection dye. · Perform a leak detection test on the complete system. · The low side test pressure must not exceed 31
bar /450 psi. · 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. · Pull down the system under a vacuum of
500 µm Hg (0.67 mbar) / 0.02 inch Hg 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 off and isolate the main power supply. · All electrical components must be selected as
per local standards and compressor requirements. · Refer to electrical connections details. For three phase applications, the terminals are labeled T1, T2, and T3. For single-phase applications the terminals are labeled C (common), S (start), and R (run).
Danfoss A/S 6430 Nordborg Denmark
· Danfoss scroll compressors will only compress gas while rotating counter-clockwise (when viewed from the compressor top). Since singlephase motors will start and run in only one direction, reverse rotation is not a major consideration. Three-phase motors, however, will start and run in either direction, depending on the phase angles of the supplied power. Care must be taken during installation to ensure that the compressor operates in the correct direction.
· Use ø 4.8 mm / #10 – 32 screws and ¼” ring terminals for the power connection with ring connect screw terminal (C type). Fasten with 3 Nm torque.
· Use ø 6.3 mm tabs for quick connect spade terminals (P type).
· Use a self tapping screw to connect the compressor to earth.
8 Filling the system
· Keep the compressor switched off. · Keep the refrigerant charge below the indicated
charge limits if possible. Above this limit; protect the compressor against liquid flood-back with a pump-down cycle or suction line accumulator. · Never leave the filling cylinder connected to the circuit.
Compressor models MLZ015-019-021-026 MLZ030-038-045-048
MLZ058-066-076
Refrigerant charge limit 3.6 kg / 8 lb 5.4 kg / 12 lb 7.2 kg / 16 lb
9 Verification before commissioning
Use safety devices such as safety pressure switch and mechanical relief valve in compliance with both generally and locally applicable regulations and safety standards. Ensure that they are operational and properly set.
Check that the settings of high-pressure switches don’t exceed the maximum service pressure of any system component. · A low-pressure switch is recommended to
avoid low pressure operation.
Minimum setting for R452A and R513A
R22,
1.5 bar (absolute)
/
22 psia
Minimum setting for R404A 1.8 bar (absolute) / 26 psia
Minimum setting for R407A 1.7 bar (absolute) / 25 psia
Minimum setting for R407F 1.9 bar (absolute) / 28 psia
Minimum setting for R134a, R448A and R449A
1.45 bar (absolute) / 21
psia
· Verify that all electrical connections are properly fastened and in compliance with local regulations.
· When a crankcase heater is required, it must be energized at least 8 hours before initial start-up and start-up after prolonged shutdown.
· Please respect a 90 Nm ± 20 Nm for tightening torque of all rotolock nut.
10 Start-up
· Never start the compressor when no refrigerant is charged.
· Do not provide any power to the compresor unless suction and discharge service valves are open, if installed.
· Energize the compressor. It must start promptly. If the compressor does not start, check wiring conformity and voltage on terminals.
· Eventual reverse rotation can be detected by following phenomena; the excessive noise, no pressure differential between suction and discharge, and line warming rather than immediate cooling. A service technician should be present at initial start-up to verify that supply power is properly phased and that the compressor is rotating in the correct direction. MLZ Scroll compressors are designed to operate for a maximum of 150 hours in reverse, but as a reverse rotation situation can go unnoticed for longer periods, phase monitors are recommended. For compressors MLZ048 and larger, phase monitors are required for all applications. Danfoss recommends phase protection for residential compressors.
· If the internal overload protector trips out, it must cool down to 60°C / 140°F to reset. Depending on ambient temperature, this may take up to several hours.
11 Check with running compressor
Check current draw and voltage. Measurement of amps and volts during running conditions must be taken at other points in the power supply, not in the compressor electrical box. · Check suction superheat to reduce risk of slug-
ging. · Observe the oil level in the sight glass (if pro-
vided) for about 60 minutes to ensure proper oil return to the compressor. · Respect the operating limits. · Check all tubes for abnormal vibration. Movements in excess of 1.5 mm / 0.06 in require corrective measures such as tube brackets. · When needed, additional refrigerant in 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 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 / 212°F 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. · Confirm 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 absence of rust and oxidation on the compressor shell, tubes and electrical connections. · Acid / moisture content in system and oil should be checked regularly.
13 – Warranty
Always transmit the model number and serial number with any claim filed regarding this product. The product warranty may be void in following cases: · Absence of nameplate. · External modifications; in particular, drilling,
welding, broken feet and shock marks. · Compressor opened or returned unsealed. · Rust, water or leak detection dye inside the compres-
sor. · Use of a refrigerant or lubricant not approved by
Danfoss. · Any deviation from recommended instructions
pertaining to installation, application or maintenance. · 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 at its site.
Danfoss can accept no responsibility for possible errors in catalogues, brochures and other printed material. Danfoss reserves the right to alter its products without notice. This also applies to products already on order provided that such alterations can be made without subsequential changes being necessary in specifications already agreed. All trademarks in this material are property of the respective companies. Danfoss and the Danfoss logotype are trademarks of Danfoss A/S. All rights reserved.
2 | © Danfoss | DCS (CC) | 2018.06
8510284P01C – FRCC.PI.048.A3.02
Documents / Resources
 | Danfoss MLZ Compressors [pdf] Instructions MLZ Compressors, MLZ, Compressors |
 | Danfoss MLZ Compressors [pdf] Instructions MLZ076, MLZ015-026, MLZ030-045, MLZ048, MLZ058-076, MLZ Compressors, Compressors |
 | Danfoss MLZ Compressors [pdf] Instructions MLZ076, MLZ015-026, MLZ030-045, MLZ048, MLZ058-076, MLZ Compressors, MLZ, Compressors |