Inverter Operation; Maximum Operating Current - Models 4Mtl-35 To 4Mtl-50; Recommendations For Use With An Inverter - Emerson Copeland 4MTL-05 Application Manuallines

5.7

Inverter operation

Stream compressors are released for inverter applications with inverters from Control Techniques or
other brands available on the market.
Compressor
4MSL-03
4MSL-04
4MSL-06
4MSL-08
4MSL-12
4MSL-15
4MTL-05
4MTL-07
4MTL-09
4MTL-12
4MTL-15
4MTL-30
4MTL-35
4MTL-40
4MTL-50
Table 14: Inverter operation – Approved frequency ranges
NOTE: The frequency range depends on the operating conditions. For approved application
envelope please contact Application Engineering or refer to Select Software at
www.climate.emerson.com/en-gb.
5.7.1 Maximum Operating Current – Models 4MTL-35 to 4MTL-50
Large Stream CO compressors from 35 to 50 hp have a different MOC in operation with frequency
2
drives. Table 15 below shows the values for both types of operation.
Compressor MOC (A)
4MTL-35 59.6
4MTL-40 67.4
4MTL-50 82.7
Table 15: Maximum operating current for large Stream CO

5.7.2 Recommendations for use with an inverter

Running the Stream CO
resonances might occur in the lower frequency ranges. This phenomenon strongly depends on the
system design and operating conditions.
Emerson conducted extensive tests to investigate compressor behaviour in terms of resonances.
The testing indicates that the following hardware variables have a significant impact on possible
resonances:
▪ Mounting parts: The rubber mounting parts supplied with Stream compressors are suitable for
the whole frequency range from 25 to 70 Hz.
▪ Piping design: It is recommended to pay particular attention to the discharge line design. A
discharge pipe parallel to the compressor axis normally gives a positive effect to reduce
resonances at low frequencies.
▪ Base frame design: The framework structure should be stiff enough to ensure that its resonance
frequencies are above the maximum 70 Hz frequency. A design with natural frequencies below
the minimum 25 Hz speed may lead to high vibrations during start-up.
AGL_Stream_ST_4MTL_4MSL_E_Rev01
Nominal
Displacement
3
m /h @ 50 Hz
power
3 hp 4.6
4 hp 6.2
6 hp 7.4
8 hp 9.5
12 hp 12.5
15 hp 17.9
5 hp 4.6
7 hp 6.2
9 hp 7.4
12 hp 9.5
15 hp 12.5
30 hp 17.9
35 hp 22.7
40 hp 26.6
50 hp 32.0
MOC (A)
VS
67.1
75.8
90.6
compressor with an inverter is a reliable application. Nevertheless
2
Approved
frequency
ranges
25 - 70 Hz
25 - 70 Hz
30 - 70 Hz
25 - 70 Hz
30 - 70 Hz
(check approved
application
envelope)
compressor
2
Recommended
mounting parts
Hard rubber kit
# 3189744
33