Marstair MMC User manual

55008381-06
TECHNICAL MANUAL
UNITS
MMC AND MCUA CONDENSING UNITS

2/21 55008381-06
CONTENTS
PAGE
GENERAL INFORMATION
3
PART NUMBERS
4-5
FEATURES & OPTIONS and KITS
6
DIMENSIONS & WEIGHTS
7
SPECIFICATION DETAILS
7-8
PERFORMANCE DATA
9
INSTALLATION
10-12
MOUNTING
12
DIMENSION DIAGRAMS
12-15
PIPEWORK
15
PIPE CONNECTIONS
16
REFRIGERANT
17
FANS
18
SERVICING
ELECTRICAL –WIRING DIAGRAM
19
20-21
INDEX

3/21 55008381-06
NOTE
The instructions included in this document must be followed at all times to guarantee the correct installation,
operation and maintenance of the system. The personnel in charge of installing, operating or servicing must
take the instructions into account at all times. The guarantee will be void if these system instructions are not
followed.
WARNING
MCUA units are specially designed for use in dangerous areas and comply with official regulations related to
the risks of explosion. The equipment might not operate correctly if the operation instructions are not
followed, the equipment is not correctly connected or is modified with no prior authorization, even in the case
of minor modifications.
The MCUA units are marked
Only qualified personnel who understand the regulations related to the risk of explosion can handle this type
of system.
Matched MMC units and evaporators are to be installed in safe areas.
All of Marstair’s equipment, including the complete line of accessories, have been manufactured with the
most rigorous manufacturing processes, quality systems and quality assurance procedures.
The equipment, testing, manufacturing and control activities comply with CEE regulations, in particular, with
current safety regulations. In addition, the materials and standardised components used to manufacture the
equipment comply with the relevant standards and are covered by the corresponding quality certificates.
The design and manufacturing processes of the different Marstair equipment have taken into account the
appropriate regulations and Risk Elimination instructions, in order to comply with the Essential Safety and
Health Requirements.
Whenever allowed by the configuration and manufacturing process, Marstair incorporates the most
appropriate Safety devices directly. If this is not possible at the factory, due to specific assembly or
application conditions, all additional Safety accessories are available and can be installed before starting the
equipment.
These accessories will cover the concept of residual risks described in the regulations.
TEV Limited recommends the installation of MAINTENANCE SWITCHES as a high safety accessory
(appropriate for use in potentially explosive environments, in accordance with Directive ATEX 94/4/CE), with
manual disconnection, allowing safe maintenance activities.
1. Marstair Ltd recommend that personnel working on this equipment be skilled and fully conversant with
the appropriate Air Conditioning, Refrigeration and Electrical practices and have sound knowledge of
current Industrial Safe Working practices.
2. These units are supplied with a dry nitrogen charge and polyolester oil.
Do not open the valves until the system is fully installed.
Do not mix oils or refrigerants.
3. These units contain live electrical components, moving parts and refrigerant under pressure. Always
site out of reach of children and protect from vandalism.
4. The data plates only give information for individual units. For system details add input power and
current of all units, including any heater load.
5. FUSES- for recommended fuse size see indoor unit instructions.
GENERAL INFORMATION

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MCUA
Part Number
Description
Case material
Frequency
- Hz
Heat Exchanger
Material
55051007
MCUA 15-30 3/60/460 SS
Stainless Steel 316
60
Copper Aluminium
55051008
MCUA 40 3/60/460 SS
Stainless Steel 316
60
Copper Aluminium
55051009
MCUA 50-80 3/60/460 SS
Stainless Steel 316
60
Copper Aluminium
55051010
MCUA 90-100 3/60/460 SS
Stainless Steel 316
60
Copper Aluminium
55051011
MCUA 130-165 3/60/460 SS
Stainless Steel 316
60
Copper Aluminium
55051012
MCUA 180-200 3/60/460 SS
Stainless Steel 316
60
Copper Aluminium
55051013
MCUA15-30 3/60/460 SS PROCOIL
Stainless Steel 316
60
Copper Aluminium Coated
55051014
MCUA40 3/60/460 SS PROCOIL
Stainless Steel 316
60
Copper Aluminium Coated
55051015
MCUA50-80 3/60/460 SS PROCOIL
Stainless Steel 316
60
Copper Aluminium Coated
55051016
MCUA90-100 3/60/460 SS PROCOIL
Stainless Steel 316
60
Copper Aluminium Coated
55051017
MCUA130-165 3/60/460 SS PROCOIL
Stainless Steel 316
60
Copper Aluminium Coated
55051018
MCUA180-200 3/60/460 SS PROCOIL
Stainless Steel 316
60
Copper Aluminium Coated
55051019
MCUA15-30 3/60/460 SS COP/COP
Stainless Steel 316
60
Copper/Copper
55051020
MCUA40 3/60/460 SS COP/COP
Stainless Steel 316
60
Copper/Copper
55051021
MCUA50-80 3/60/460 SS COP/COP
Stainless Steel 316
60
Copper/Copper
55051022
MCUA90-100 3/60/460 SS COP/COP
Stainless Steel 316
60
Copper/Copper
55051023
MCUA130-165 3/60/460 SS COP/COP
Stainless Steel 316
60
Copper/Copper
55051024
MCUA180-200 3/60/460 SS COP/COP
Stainless Steel 316
60
Copper/Copper
55051043
MCUA 15-30 3/50/460 SS
Stainless Steel 316
50
Copper Aluminium
55051044
MCUA 40 3/50/460 SS
Stainless Steel 316
50
Copper Aluminium
55051045
MCUA 50-80 3/50/460 SS
Stainless Steel 316
50
Copper Aluminium
55051046
MCUA 90-100 3/50/460 SS
Stainless Steel 316
50
Copper Aluminium
55051047
MCUA 130-165 3/50/460 SS
Stainless Steel 316
50
Copper Aluminium
55051048
MCUA 180-200 3/50/460 SS
Stainless Steel 316
50
Copper Aluminium
55051049
MCUA15-30 3/50/460 SS PROCOIL
Stainless Steel 316
50
Copper Aluminium Coated
55051050
MCUA40 3/50/460 SS PROCOIL
Stainless Steel 316
50
Copper Aluminium Coated
55051051
MCUA50-80 3/50/460 SS PROCOIL
Stainless Steel 316
50
Copper Aluminium Coated
55051052
MCUA90-100 3/50/460 SS PROCOIL
Stainless Steel 316
50
Copper Aluminium Coated
55051053
MCUA130-165 3/50/460 SS PROCOIL
Stainless Steel 316
50
Copper Aluminium Coated
55051054
MCUA180-200 3/50/460 SS PROCOIL
Stainless Steel 316
50
Copper Aluminium Coated
55051055
MCUA15-30 3/50/460 SS COP/COP
Stainless Steel 316
50
Copper/Copper
55051056
MCUA40 3/50/460 SS COP/COP
Stainless Steel 316
50
Copper/Copper
55051057
MCUA50-80 3/50/460 SS COP/COP
Stainless Steel 316
50
Copper/Copper
55051058
MCUA90-100 3/50/460 SS COP/COP
Stainless Steel 316
50
Copper/Copper
55051059
MCUA130-165 3/50/460 SS COP/COP
Stainless Steel 316
50
Copper/Copper
55051060
MCUA180-200 3/50/460 SS COP/COP
Stainless Steel 316
50
Copper/Copper
PART NUMBERS

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MMC
Part Number
Description
Frequency
- Hz
With Neutral Star
No Neutral Delta
55052001
MMC30 3/50/400
50
Star
55052002
MMC40 3/50/400
50
Star
55052003
MMC50 3/50/400
50
Star
55052004
MMC60 3/50/400
50
Star
55052005
MMC80 3/50/400
50
Star
55052006
MMC90 3/50/400
50
Star
55052007
MMC100 3/50/400
50
Star
55052008
MMC130 3/50/400
50
Star
55052009
MMC150 3/50/400
50
Star
55052010
MMC165 3/50/400
50
Star
55052011
MMC180 3/50/400
50
Star
55052012
MMC200 3/50/400
50
Star
55052013
MMC40 3/60/460
60
Star
55052014
MMC50 3/60/460
60
Star
55052015
MMC60 3/60/460
60
Star
55052016
MMC80 3/60/460
60
Star
55052017
MMC90 3/60/460
60
Star
55052018
MMC100 3/60/460
60
Star
55052019
MMC130 3/60/460
60
Star
55052020
MMC150 3/60/460
60
Star
55052021
MMC165 3/60/460
60
Star
55052022
MMC180 3/60/460
60
Star
55052023
MMC200 3/60/460
60
Star
55052024
MMC30 3/50/460 DELTA
50
Delta
55052025
MMC40 3/50/460 DELTA
50
Delta
55052026
MMC50 3/50/460 DELTA
50
Delta
55052027
MMC60 3/50/460 DELTA
50
Delta
55052028
MMC80 3/50/460 DELTA
50
Delta
55052029
MMC90 3/50/460 DELTA
50
Delta
55052030
MMC100 3/50/460 DELTA
50
Delta
55052031
MMC130 3/50/460 DELTA
50
Delta
55052032
MMC150 3/50/460 DELTA
50
Delta
55052033
MMC165 3/50/460 DELTA
50
Delta
55052034
MMC180 3/50/460 DELTA
50
Delta
55052035
MMC200 3/50/460 DELTA
50
Delta
55052036
MMC40 3/60/460 DELTA
60
Delta
55052037
MMC50 3/60/460 DELTA
60
Delta
55052038
MMC60 3/60/460 DELTA
60
Delta
55052039
MMC80 3/60/460 DELTA
60
Delta
55052040
MMC90 3/60/460 DELTA
60
Delta
55052041
MMC100 3/60/460 DELTA
60
Delta
55052042
MMC130 3/60/460 DELTA
60
Delta
55052043
MMC150 3/60/460 DELTA
60
Delta
55052044
MMC165 3/60/460 DELTA
60
Delta
55052045
MMC180 3/60/460 DELTA
60
Delta
55052046
MMC200 3/60/460 DELTA
60
Delta

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DESCRIPTION
MMC
MCUA
Easy access for installation and service


Suction and liquid services valves


Capacitor start relay 1ph (MMC 30-40)

n/a
PTC resistor 1ph

n/a
Hot gas bypass valve

n/a
LP cut-out auto

n/a
HP cut-out auto

n/a
Isolator

n/a
3 minute start time delay

n/a
Wall mount brackets

n/a
Contactor

n/a
Over load (standard on 3ph)

n/a
Low ambient start

n/a
= Standard = Option n/a = Not applicable
MMC
DESCRIPTION
MODEL
PART NUMBER
Pressure switch (HP manual)
All
55000398
Volt free relay
All
55000395
Wall mount brackets
30-80
55021100
90-200
55021101
Overload (standard on 3ph)
30
55000410
40-60
55000446
80-90
55000449
30-40
55000412
PTC (hard start 1ph)
40
55000414
CSR (hard start 1ph)
30
55000415
1ph 30-60
55000419
Isolator for remote mounting
1ph 80-90
55000418
3ph All
55000419
Reciprocating 30-40
55000454
Compressor jacket
Scroll 50-80
55000455
Scroll 90-180
55000456
Scroll 200
55000457
FEATURES AND OPTIONS
KITS

7/21 55008381-06
UNPACKED
MCUA
Model
30
40
50-80
90-100
130-165
180-200
Height mm
620
620
720
820
1080
1275
Width mm
900
900
1000
1000
1000
1100
Depth mm
511
511
511
561
636
636
Weight kg
22
25
33
37
58
68
MMC
Model
30
40
50
60
80
90
100
130
150
165
180
200
Height mm
700
700
700
700
700
700
700
700
700
700
700
700
Width mm
480
480
480
480
480
480
480
480
480
480
480
480
Depth mm
475
475
475
475
475
475
475
475
475
475
475
475
Weight kg
41
43
43
44
45
51
53
56
59
64
65
85
MMC & MCUA
30
40
50
60
80
90
100
130
150
165
180
200
Nominal cooling
capacity
kW
3.7
4.2
5.8
7.0
7.4
8.2
10.9
12.4
13.9
14.7
17.1
19.9
3Ph (400v 50Hz) MMC
Power (nominal)
kW
-
-
1.6
2.0
1.9
2.4
3.0
4.1
4.3
4.4
5.3
6.0
7.0
9.4
Starting current LRA
A
-
-
18
22
26
32
40
48
51
62
68
71
71
98
Nominal current FLA
A
-
-
3.6
4.8
4.2
4.2
4.9
7.1
7.2
7.7
8.7
9.5
11.9
16.9
Condenser Fan
MCUA
Model
30
40
50-80
90-100
130-165
180-200
Airflow (m³/s)
0.97
0.97
0.97
0.97
1.85
1.85
Max Current @ 400V
(A)
1.05
1.05
1.05
1.05
2.1
2.1
Fans :no x diameter
(mm)
1 x 400
1 x 400
1 x 400
1 x 400
2 x 400
2 x 400
Fan max speed (RPM)
1400
1400
1400
1400
1400
1400
Condenser fan sound power
Frequency
125
250
500
1000
2000
4000
dB(A)
45
57
65
70
70
66
SPECIFICATION DETAILS

8/21 55008381-06
MMC Sound power
levels
Frequency Hz
MMC
125
250
500
1K
2K
4K
dBA
30
66
61
65
59
53
48
65
40
66
61
65
58
53
48
65
50
67
64
66
64
59
52
68
60
67
64
67
67
61
52
70
80
69
67
67
62
56
52
68
90
79
65
65
62
59
54
68
100
75
69
71
64
60
54
70
130
65
67
68
66
63
53
70
165
66
67
67
65
64
54
73
180
66
36
67
61
65
55
73
200
67
66
68
67
66
57
76

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MMC & MCUA CAPACITIES
MODEL
AIR ON TO
CONDENSER
°C
SATURATED SUCTION TEMPERATURE °C
-2.5
0
2.5
5
7.5
10
COOLING CAPACITY AND POWER INPUT kW
CAP.
POWER
CAP.
POWER
CAP.
POWER
CAP.
POWER
CAP.
POWER
CAP.
POWER
MMC &
MCUA 30
25
2.87
1.02
3.22
1.05
3.53
1.06
3.74
1.04
4.12
1.07
4.49
1.10
30
2.71
1.10
3.06
1.13
3.27
1.12
3.51
1.12
3.84
1.15
4.19
1.18
35
2.59
1.20
2.82
1.20
3.03
1.19
3.36
1.23
3.68
1.26
3.79
1.22
40
2.38
1.27
2.17
1.32
2.80
1.26
3.12
1.31
3.32
1.31
3.62
1.35
45
2.11
1.30
2.43
1.36
2.53
1.31
2.84
1.37
MMC &
MCUA 40
25
3.38
1.13
3.70
1.15
4.02
1.16
4.35
1.18
4.67
1.19
5.00
1.21
30
3.19
1.22
3.50
1.24
3.81
1.26
4.11
1.28
4.42
1.30
4.73
1.32
35
3.01
1.31
3.30
1.33
3.59
1.36
3.88
1.38
4.17
1.41
4.46
1.43
40
2.84
1.40
3.11
1.43
3.37
1.47
3.63
1.50
3.89
1.53
4.15
1.56
45
2.68
1.51
2.91
1.55
3.15
1.58
3.38
1.62
3.61
1.66
3.85
1.70
MMC &
MCUA 50
25
4.57
1.87
5.09
2.03
5.51
2.14
5.97
2.25
6.41
2.38
6.79
2.51
30
4.34
1.95
4.75
2.09
5.25
2.19
5.63
2.32
6.04
2.45
6.49
2.58
35
3.94
2.00
4.42
2.13
4.91
2.24
5.29
2.36
5.75
2.49
6.09
2.65
40
3.76
2.05
4.22
2.18
4.58
2.29
5.04
2.41
5.39
2.58
5.69
2.74
45
3.50
2.12
3.93
2.22
4.37
2.35
4.69
2.48
MMC &
MCUA 60
25
5.43
2.22
6.02
2.27
6.61
2.31
7.21
2.37
7.80
2.42
8.39
2.47
30
5.06
2.46
5.64
2.51
6.22
2.56
6.80
2.62
7.39
2.67
7.97
2.73
35
4.77
2.72
5.33
2.78
5.89
2.83
6.45
2.89
7.01
2.95
7.57
3.01
40
4.39
3.01
4.91
3.07
5.43
3.13
5.95
3.19
6.47
3.26
6.99
3.32
45
4.02
3.32
4.49
3.40
4.97
3.46
5.45
3.53
5.93
3.60
MMC &
MCUA 80
25
6.07
2.26
6.64
2.31
7.21
2.37
7.79
2.42
8.36
2.47
8.93
2.53
30
5.68
2.49
6.23
2.54
6.77
2.60
7.32
2.66
7.87
2.71
8.42
2.77
35
5.28
2.72
5.81
2.78
6.33
2.83
6.86
2.89
7.38
2.95
7.91
3.01
40
4.90
3.03
5.39
3.10
5.88
3.16
6.37
3.23
6.86
3.29
7.35
3.36
45
4.52
3.35
4.97
3.42
5.43
3.49
5.88
3.56
6.33
3.63
MMC &
MCUA 90
25
7.16
2.89
7.71
2.95
8.26
3.01
8.81
3.06
9.36
3.12
9.91
3.18
30
6.69
3.17
7.21
3.24
7.74
3.30
8.27
3.36
8.79
3.42
9.32
3.48
35
6.22
3.46
6.72
3.52
7.22
3.59
7.72
3.65
8.23
3.72
8.73
3.78
40
5.80
3.79
6.27
3.86
6.74
3.93
7.22
4.00
7.69
4.07
8.17
4.14
45
5.38
4.12
5.82
4.20
6.27
4.27
6.71
4.34
7.16
4.42
7.60
4.49
MMC &
MCUA 100
25
7.87
3.18
9.10
3.42
10.40
3.66
11.52
3.87
12.61
3.87
13.83
3.86
30
7.60
3.23
8.73
3.88
9.68
3.81
10.71
4.05
11.66
4.18
12.71
4.29
35
7.00
3.24
8.06
3.56
9.03
3.87
9.92
4.13
10.91
4.31
11.89
4.52
40
6.17
3.16
7.12
3.54
8.14
3.86
8.91
4.17
9.86
4.47
10.80
4.75
45
5.12
2.95
6.18
3.47
7.07
3.89
7.89
4.25
MMC &
MCUA 130
25
9.69
3.14
10.71
3.46
11.72
3.73
12.76
4.01
13.71
4.28
14.56
4.54
30
9.09
3.16
10.07
3.46
11.11
3.74
12.12
4.08
13.05
4.36
13.93
4.68
35
8.27
3.27
9.32
3.61
10.27
3.91
11.34
4.25
12.41
4.56
13.29
4.91
40
7.61
3.29
8.58
3.65
9.54
4.01
10.44
4.31
11.46
4.68
45
6.89
3.34
7.63
3.68
8.68
4.09
MMC &
MCUA 150
25
11.06
3.73
12.26
4.13
13.26
4.46
14.30
4.82
15.24
5.15
16.19
5.47
30
10.42
3.75
11.52
4.14
12.56
4.48
13.57
4.88
14.56
5.24
15.48
5.63
35
9.46
3.89
10.59
4.32
11.61
4.68
12.69
5.08
13.77
5.47
14.77
5.90
40
8.70
3.90
9.79
4.35
10.76
4.78
11.67
5.15
45
7.90
3.98
8.89
4.40
MMC &
MCUA 165
25
11.97
4.13
13.30
4.57
14.29
4.95
15.32
5.36
16.26
5.73
17.28
6.09
30
11.31
4.15
12.49
4.59
13.52
4.98
14.54
5.42
15.57
5.82
16.51
6.26
35
10.26
4.30
11.44
4.79
12.51
5.19
13.59
5.64
14.67
6.08
15.75
6.56
40
9.43
4.31
10.60
4.81
11.58
5.29
12.49
5.17
45
8.57
4.41
MMC &
MCUA 180
25
13.42
4.71
14.97
5.12
16.28
5.45
17.63
5.79
18.86
6.13
20.27
6.47
30
12.74
4.75
14.13
5.16
15.39
5.51
16.76
5.90
18.08
6.26
19.34
6.64
35
11.52
4.94
12.94
5.38
14.34
5.76
15.67
6.16
17.12
6.56
18.51
6.98
40
10.63
4.96
11.97
5.44
13.28
5.89
14.43
6.26
15.95
6.74
17.31
7.18
45
9.72
5.10
10.95
5.61
12.17
6.09
13.31
6.49
14.63
6.98
MMC &
MCUA 200
25
15.28
5.37
16.96
5.90
18.96
6.47
21.12
6.87
22.34
7.28
23.48
7.65
30
14.42
5.41
16.01
5.92
17.73
6.41
19.75
6.96
21.18
7.40
22.52
7.88
35
13.13
5.51
14.68
6.17
16.49
6.68
18.30
7.23
19.88
7.74
21.48
8.27
40
12.03
5.62
13.59
6.24
15.13
6.82
16.58
7.31
18.33
7.92
45
10.99
5.78
12.36
6.42
13.80
7.03
NOTE: OPERATION IN THE SHADED AREAS OF THE TABLE WILL RESULT IN UNACCEPTABLY HIGH CONDENSING
TEMPERATURE AND SHOULD BE AVOIDED.
PERFORMANCE DATA

10/21 55008381-06
1. Commissioning
1.1 Reception verification
The packaging must not show any signs of incorrect handling at reception. Perform a visual inspection of the
equipment to make sure that it has not been damaged during transport and that the damage does not affect
the correct operation. If external damage is observed, report it to the carrier and the Commercial Department
of TEV Limited.
Turn the propeller or the fan. There should be no unwanted stress or tension.
Check the model to ensure its characteristics correspond to those included in the delivery note.
Check all information in the plate of characteristics of the equipment, including category and type of
protection, as well as ensuring the motor plate marks comply with those of the electrical installation, voltage,
frequency, etc.
All equipment manufactured by TEV Limited are verified and tested after being assembled. (Check all
accessories to ensure they are in good condition, if applicable).
2. Handling
2.1 Transport
The equipment is supplied on a palette or in a crate, to avoid damaging the equipment.
2.2 Conservation and storage
The equipment must be stored inside a warehouse, in dry environments with no vibrations or dust.
2.3 Lifting
The units should be lifted by using fork lifts the unit. Special attention should be paid to avoid the unit tilting
on the fork lift.
2.4 Installation
All certification-related values described in the plates of characteristics must be carefully checked, in order to
ensure the protection of the equipment, environment and area are compatible with the equipment.
2.5 Fan / Motor assemblies are packed separately to prevent transit damage so must be fitted during
installation.
Standards EN 1127-1 (Prevention and protection against explosions) and EN 13463-1 (Non-electrical
equipment used in potentially explosive environments) must be observed.
NOTE
The instruction manual of the fan manufacturer is included in each unit. The following indications must be
observed:
-Ground connection.
-Connection of the power supply cable and terminals, in compliance with EN 60204-1.
-Use of certified stuffing boxes for increased safety and fireproof motors, with the adequate IP protection.
INSTALLATION

11/21 55008381-06
The units manufactured by Marstair have been specially designed to allow easy assembly on walls and
floors.
Ensure the fan heat exchanger is not deformed mechanically during installation.
The location, arrangement and dimensions of fixing drills are standardised and are designed to offer the level
of safety and stability required.
The unit must be firmly fixed to the support structure with screws and washers, using the drills in the
envelope frame (helicoidal) or support or suction inlets and discharge outlets (centrifugal).
Fixing bolts which have not been properly tightened will produce harmful noises and vibrations.
WARNING
Ensure there are no unwanted particles in the frame and conduits before starting the fan, including any loose
elements that could be dragged by the flow of air and cause damage.
The following points must be taken into account for the correct assembly of the equipment:
a. Follow the general safety instructions during installation.
b. Observe the correct location measures with no interference.
c. Distance between fixing holes must match that of the unit.
d. The screws used will have the correct dimensions, quality and resistance required to support the load of
the unit.
e. Use the appropriate tools and follow the correct assembly instructions to avoid overcharging the unit.
WARNING
Rotating parts of the fan (mainly propellers and turbines) are VERY DANGEROUS elements.
The propeller or turbine must rotate freely with no added tension after the mechanical assembly. The unit
can only operate at the voltage described in the motor’s plate of characteristics.
All electrical characteristics included on the plate must comply with the power supply network characteristics,
voltage (V) and frequency (Hz).
The equipment can be connected after the first test has been carried out, in compliance with the instructions
of the low voltage regulations.
a. The correct cable section (mm2) with the corresponding motor power and consumption (A) will be used.
b. Disassemble the top cover of the motor terminal box and prepare the arrangement of the said terminals,
as required for a correct connection. Layouts and diagrams must be observed at all times when connecting
the terminals.
c. The motor terminal box will always include a diagram of connections.
d. The motor’s power supply will be disconnected during these operations. After connecting the motor with
the power supply disconnected, the terminals will be checked to verify they are correctly tightened, with the
adequate grounding connection(earth).
e. The power supply cable must not have any sort of interferences or be in contact with the rotating parts of
the fan or mobile connections.
f. Connect the MCUA to the power supply and start it, verify the correct rotation direction and check the level
of consumption (intensity A), which should be correct and equivalent to the nominal intensity of the motor.
See instructions to change the rotation direction.
WARNING
Disconnect the MCUA before checking or handling the equipment and wait until the propeller or turbine has
stopped.
The risk of an explosive environment at work should be avoided at all times.
NOTE
The following must be verified after the first hour of operation:
- Motor consumption (A),
- fixing and tightening of fixing screws
3. Safety issues
MCUA units are manufactured to work under potentially explosive environments require special attention.
Said units must be installed and used by qualified personnel who understand the national safety regulations
and legislation.

12/21 55008381-06
The safety equipment required to prevent accidents during installation and operation must be used, in
accordance with local regulations.
Important Information
3.1 Do not rest or climb on the unit
3.2 Ensure that the unit is adequately grounded
MOUNTING MMC & MCUA
Whether floor or wall mounted, it is essential that the mounting surface is capable of supporting the unit
weight. Leave space around the unit for air circulation and access for installation and maintenance.
MCUA Air circulation guide
Dimensions in mm.
MMC Units must be installed in a safe area.&WEIGHTS MCU+
DIMENSIONS
MCUA 15-40
1500 min air off
100 min 100 min
600 min

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MCUA 50-80
MCUA 90-100

14/21 55008381-06
MCUA 130-165
MCUA 180-200

15/21 55008381-06
PIPEWORK
MMC 15-180
CALCULATING EQUIVALENT LENGTHS
The effects of bends and fittings must be taken into account. The table on top of page 5 covers the fittings
most likely to be encountered in installation.
ACTUAL PIPE LENGTH + TOTAL EQUIVALENT FITTING LENGTHS = TOTAL EQUIVALENT LENGTH
FITTING LOSSES in equivalent straight lengths of pipes (m)
Pipe sizes are based on:
Minimum of 2.5 m/s (500 fpm) suction gas velocity for horizontal or downflow.
Minimum of 5.0 m/s (1000 fpm) suction gas velocity for upflow.
Maximum of 20.0 m/s (4000 fpm) suction gas.
FITTING
PIPE SIZE (outside diameter in inches)
INSTALLERS TABLE
Nº OF
FITTINGS
EFFECTIVE
LENGTH
⅜
½
⅝
¾
⅞
1⅛
45° Bend
0.12
0.15
0.18
0.21
0.24
0.30
90° Bend R/d = 1
0.37
0.43
0.49
0.55
0.61
0.79
90° Bend R/d = 2
0.24
0.27
0.30
0.37
0.43
0.52
180° Bend C/d = 1
0.73
0.91
1.10
1.28
1.46
1.83
180° Bend C/d = 2
0.46
0.55
0.64
0.76
0.85
1.07
90° Elbow
0.67
0.85
1.04
1.25
1.46
1.89
R = Radius of bend
d = Diameter of tube
C = Centres of bend
TOTAL =

16/21 55008381-06
Where vertical risers exceed 3m, oil traps must be formed in the pipe. This will help ensure that oil returns to
the compressor. Typically fit an oil trap every 3m with a trap at the bottom of the riser.
The equivalent pipe run should be 45m maximum, including a maximum lift of 7.5m. Fully insulate the
suction line. Ensure the suction pipe is insulated well over the drain tray at the indoor unit. Liquid lines should
be routed to avoid hot areas. This prevents flash gas forming, which may result in erratic control of liquid
refrigerant to the evaporator.
GOOD PRACTICE
▪Keep pipe runs as short as possible.
▪Avoid sharp bends
▪Fully insulate both suction and expansion including mechanical connections
▪Try to avoid running pipes through hot areas.
PIPE SIZES
PIPE CONNECTIONS
MMC
Model
30
40
50
60
80
90
100
130
150
165
180
200
Discharge
1/2
1/2
1/2
5/8
5/8
3/4
3/4
3/4
3/4
3/4
3/4
3/4
Suction
1/2
1/2
1/2
5/8
5/8
3/4
3/4
3/4
3/4
3/4
3/4
3/4
MCUA
Model
30
40
50-80
90-100
130-165
180-200
Discharge
1/2
1/2
5/8
3/4
3/4
3/4
Liquid
3/8
3/8
1/2
1/2
1/2
1/2
INTERCONNECTING PIPEWORK
1. MMC and MCUA units have a low pressure charge of N2, which may be safely released into the
atmosphere before connection. The service valves on the units should remain closed (IN, fully
clockwise) until pipework has been fitted, to avoid unnecessary moisture ingress.
2. Connecting the pipework
a. Remove the flare nuts from the suction, discharge and liquid service valves.
b. Ensure that the suction line is fully insulated: if an expansion line is used this should also be fully
insulated.
c. Place the flare nuts over the incoming pipework and flare the pipe ends. The use of a little
refrigeration oil on the flaring tool will help.
d. Connect the pipework between the units. Do not leave pipe ends, valves etc. open to the
atmosphere.
R407C is very hygroscopic, and will absorb damaging levels of moisture if left open.
MMC MCUA 0-6m 6-15m 15-21m 21-45m 0-6m 6-15m 15-21m 21-45m 0-21m 21-45m
30 30 1/2 5/8 5/8 5/8 1/2 1/2 5/8 5/8 1/4 3/8
40 40 1/2 5/8 5/8 3/4 1/2 5/8 5/8 3/4 3/8 3/8
50 50-80 1/2 5/8 3/4 3/4 1/2 5/8 3/4 3/4 3/8 1/2
60 50-80 5/8 3/4 3/4 7/8 5/8 5/8 3/4 7/8 3/8 1/2
80 50-80 5/8 3/4 3/4 7/8 5/8 3/4 3/4 7/8 3/8 1/2
90 90-100 5/8 3/4 3/4 7/8 5/8 3/4 3/4 7/8 3/8 1/2
100 90-100 3/4 7/8 7/8 1 1/8 5/8 3/4 3/4 7/8 3/8 5/8
130 130-165 3/4 7/8 7/8 1 1/8 3/4 3/4 7/8 1 1/8 1/2 5/8
150 130-165 3/4 7/8 7/8 1 1/8 3/4 7/8 7/8 1 1/8 1/2 5/8
165 130-165 3/4 7/8 1 1/8 1 1/8 3/4 7/8 1 1/8 1 1/8 1/2 5/8
180 180-200 7/8 1 1/8 1 1/8 1 3/8 3/4 7/8 1 1/8 1 1/8 1/2 5/8
200 180-200 7/8 1 1/8 1 1/8 1 3/8 7/8 1 1/8 1 1/8 1 3/8 1/2 5/8
Suction
Discharge
Liquid

17/21 55008381-06
REFRIGERANT
Always use two spanners when tightening the flare nuts to avoid twisting the pipes. Use a small
amount of refrigerant oil on the mating surfaces.
e. Sight glasses and filter driers are not necessary, but if required should be fitted between the
outdoor unit liquid shut off valve and the expansion device.
EVACUATING
With the valves closed, connect a vacuum pump to the service ports on the outdoor unit valves. Evacuate
the interconnecting pipework and indoor unit to 1000 microns (1 Torr) or better. Allow this to be held for a
minimum of 15 minutes.
1. Release the nitrogen holding charge in the indoor and outdoor units to atmosphere. Open the valves
(hex drive fully out) using a 5mm Allen key. Connect a vacuum pump to the service ports on the
outdoor unit valves and evacuate the system to 1000 microns (1 Torr) or better and allow to be held
for a minimum of 15 minutes.
2. Replace the caps on the service ports, (torque to 25NM).
ELECTRICAL
R407C Refrigerant charge for 3mm liquid line
MMC
30
1000
40
1240
50
1690
60
2000
80
1880
90
2060
100
2520
130
4170
150
4170
165
4540
180
4640
200
5480
Charge in g per extra meter of liquid line
1/4
20
3/8
50
1/2
80
5/8
110
KVC Suction Pressure Regulators
Turning clockwise gives higher pressure and turning counter clockwise gives
lower pressure. Set the suction pressure to between 3.5 and 4 bar.
After the system has been in normal operation for a time, fine adjustment is
necessary. Always use a pressure gauge when making fine adjustments.
Remember to always replace the protective cap on the setting screw after final
setting

18/21 55008381-06
FANS
1. FANS
The fans fitted to MCUA units can be used in potentially explosive environments. Said fans have the CE
mark in the plate of characteristics and comply with the following:
-ATEX 94/9/CE Directive.
-98/37/CE Machinery Directive.
-Including the following standards:
•EN 13463-1;Non-electrical equipment, used in potentially explosive environments.
•EN 1127-1; Explosive environments. Prevention and protection against explosions.
•EN ISO 12100-1; Machinery safety. Basic concepts.
•EN ISO 12100-2; Machinery safety. Basic concepts.
•EN 294; Machinery safety. Safety distance to avoid touching dangerous areas with the top limbs.
•ISO 13852; Machinery safety. Safety distance to avoid touching dangerous areas with the top limbs.
•UNE 100250; (ISO 12499) Industrial fans. Mechanical safety of fans.
•ISO 3744; Acoustics. Determination of sound power levels.
•ISO 1940-1; Mechanical vibration. Balancing quality.
•ISO 10816-1; Mechanical vibration. Evaluation of machine vibrations.
2.Validity
These instructions are valid for the units manufactured by Marstair, with the construction required to operate
in potentially explosive environments (Ex II 2 G).
3. Previous Verifications
We advise that you check the requirements related to methods of protection in explosive environments, for
example:
a) Group of gases
b) Type of temperature
Temperature class
Ignition
temperature for gas
/ steam ºC
Maximum
temperature
allowed in the
equipment ºC
T4
>135 <200
135
The maximum temperature is calculated with a room temperature of 40°C
The units are not suitable for use below -20°C

19/21 55008381-06
SERVICING
WARNING
The servicing activities will only be carried out after it has been turned off.
MCUA and MMC have a functional design and robust construction. Therefore, they do not require much
servicing activities for a correct operation.
The fan motor metallic parts are protected against rust with a rustproof paint finish (free from steel rust) and
are dried at a temperature of 200ºC in a furnace after the degreasing and phosphate coating process.
A series of external agents require the observance of a set of precautions to obtain the best performance of
the rotating equipment.
1. Motor
The motor must be clean at all times, since large quantities of dust particles between the cooling fins or air
inlets can overheat the motor.
The connections of the terminal box should be checked (in case they can be easily accessed) to verify the
correct tension of the bolts and screws.
2. Propellers
The propellers are balanced dynamically in accordance with the following standard: ISO 1940-1 and quality
level Q6,3.
A high level of vibration should be avoided at all times. The best method to define the variations encountered
in the smooth operation of the equipment is the measurement of the mechanical vibrations in bearings and
drive motors. The safest method to define the said vibrations is the comparison of values measured
throughout a long period of time. If there is a big variation in the values, the possible causes should be
studied, for example: dirt in the propeller or turbine. In this case, the said elements should be cleaned and
the unit should be balanced again.
The propellers and turbines should be cleaned periodically, since the dust and residues deposited in its
blades or fins decrease the performance and progressively unbalance the equipment, which affects the
operation.
Check for any unwanted interference caused by dust or residues between the rotating element (propeller or
turbine) and fixed or enveloping parts of the motor.
These operations must be carried out with the correct equipment. A standardised extraction device should
be used to disassemble the propeller or turbine. Specific tools should be used to change bearings, ensuring
the axis or bearing covers are not damaged.
3. Bearings
To avoid early faults and stops, each bearing should be checked regularly. Avoid the presence of unwanted
elements, dirt and humidity.
In delicate machines, control the detection of noise and temperature increases, which might result in serious
operation problems.
4. Heat Exchanger
The heat exchanger should be cleaned regularly to maintain system performance

20/21 55008381-06
WIRING DIAGRAM