Technology

Working safely with compressed air tank

02/01/2019

Safely using of compressed air tank is a very important issue, compressed air tank before being used must be tested by KTAT, registered for use following regulations. Users must hand over the managing responsibility the compressed air tank to the equipment manager in writing. Operating of thetanks is only given to people from 18 years old or older, who are physically fit and well-trained. They must be assigned by the employer in writing.

Guide of air filter maintenance

02/01/2019

Compressed air system in factory plays an important role. In order to ensure the stable operation during the manufacturing process, the regulary maintenance is nescessary . However, there are many different problems in fact such as: Air compressors, dusty air dryers, high engine room temperatures, unsecured wind convection ... lead to reduce using time of compressor accessories (air filter, oil filter, oil separator ...). On the other hand, the recommended maintenance in some factories is not seriously followed and there are deviations. To extend the life of the machine as well as compressor components and ensure operator safety Air compressors are very important to maintain regularly and technically correct.Air compressors, dusty air dryers, high engine room temperatures, unsecured wind convection ... lead to reduced use time of compressor accessories (air filter, loc oil, oil separator ...). On the other hand, the maintenance (maintenance) recommended by the manufacturer in some factories is not guaranteed and there are deviated. To lengthen longevity of mạchine as well as compressor components and ensure operator safety , air compressors are very important to maintain regularly and technically .

Compressors equipment maintenance

21/12/2018

Each compressor requires well-timed service. Under the service means change the oil, replacement of the oil and air filter, separator, check the belt tension (if it is not the compressor with direct drive), lubrication of the bearings, different type of the valve checking, replacement of the valves if necessary. Also according to the operational manual it is necessary to replace inlet valve repairing kit, minimum pressure valve, thermostat valve and return valve.

Safety when using GRH3 air compressor

29/07/2019

Air compressor operation requires competence and experiences. The users may get some serious injuries in some cases. For the safety purpose, read the cautions and warning specified in the manual carefully and fully understand them for proper use.

Desiccants for Absorption air dryer

26/12/2018

Activated alumina/Desiccant beads have a white, spherical, non-toxic, odorless, insoluble in water and alcohol. They are able to stand out thermal shock and abrasion with highly mechanical stability and strong absorption (impervious). The particle shape does not expand or crack after absorbing.

Electric wiring and Power Facilities of GRH3 air compressor

Monday - 29/07/2019 03:54

Electric wiring of GRH3 air compressor

1. Cabling of GRH3 air compressor

The lead-in cabling to the compressor should be executed by an competent engineer. Any poor wiring may cause electic shock or other electric fault. Do not alter control parts or electric circuits attached to the electric box. The compressor may be damaged due to malfunction of protection. When opening the electric box door for routine maintenance or repairs, the main power should be turned off to avoid any electric shock accident.

2.Wiring of GRH3 air compressor

The compressor is already wired internally. If opening the front door, you may find a hole for lead-in power cable on the bottom of the right side. Insert a wire into the hole for connection.
If open the front door, there is TB1. Please connect the power to it.
In case of wiring to the electric box, use the rubber bushing to protect the cable shearth and wire it to avoid of the shearth.
3.Power cable specifications
Use the EV or CV cable for 600V. For the thickness refer to page 24.
Rated current of main motor

Main motor cap.	AC220V	AC380V	AC440V
15(kW)	48A	28A	24A
18(kW)	58A	33A	29A
22(kW)	71A	41A	35A
27(kW)	87A	50A	43A
37(kW)	119A	69A	60A
55(kW)	178A	103A	89A
75(kW)	242A	140A	121A
110(kW)	356A	206A	178A
150(kW)	486A	281A	243A

*The rated current may vary depending on a motor type
4. Grounding
Grounding in accodance with the KSC rules. The grounding terminal inside the compressor’s electric box is located as presented in the below figure.

Attach a circuit breaker for wiring on the primary power supply of the compressor. For the capacity of the breaker, refer to page 24. When repairing or maintaining the compressor, make sure to turn if off first.

Example of circuit-breaker wiring.

5. Routine checkpoints

Connecting to TBI of the compressor’s electric box.

If any impurities or dust is found inside when visually inspecting it, turn it off and clean it up with compressed air.

Black cable is power cable and the red/white/blue insulation tubes are inserted at the end of it. If the colors of insulation tubes are discolored to black, check the tightness of screws.

If screws are loosely tightened, it may generate heat, deteriorating cables and probably leading to a fire, so they should be maintained once a month.

Cable checkpoints.

6. Check motor insulation resistance

Take the following steps if insulation resistance is to be checked, for instance, operation of circuitbreaker. 1) Turn off the power of the compressor. 2) Set the voltage range of insulation resistance tester lower than 500V. 3) How to check the resistance; Loosen the bolt with (motor’s cable) and separate the cable from the terminal.

If it displays 10MΩ and over as the above, it is norma

Power Facilities of GRH3 air compressor.
1.Cable thickness.
Since the compressor may not work properly depending on the power facility capacity and the thickness/length of the power cable and it may stop due to voltage dropping of control circuit or defective acceleration of the main motor, make sure to supply the power with the voltage dropping set within 5% of the rated power.
For the cable thickness of the lead-in cable, refer to the following table.

Main motor cap(kW)		15(18)	22(27)	37
Cable thickness	AC220	14	22	60
(mm2)	AC440	8	14	38
55	75	110	150	180
100	125	200	250	325
60	60	150	200	250

It is recommended that the cable length between a transformer/distribution board and the compressor is 100m and shorter; if longer than the length, the thickness may need reselecting.
2.Grounding specifications.
Grounding specifications are as follows.

Voltage	Grounding type	Grounding resistance
AC220A	Type 3	100Ω and lower
AC400A	Special type 3	10Ω and lower

3.Thickness of grounding cable (Bề dầy của dây nối đất)

Rated current	Cable thickness
20A and lower	2.0 and thicker
30A and lower	2.0 and thicker
50A and lower	3.5and thicker
100A and lower	5.5 and thicker
150A and lower	8.0 and thicker
200A and lower	14 and thicker
400A and lower	22 and thicker
600A and lower	38 and thicker

4. Circus breaker capacity.
The main power supply essentially needs a circuit breaker to avoid electric shock and protect the motor.
When selecting a breaker, refer to the following table.

4.1. Electric wiring

The lead-in cabling to the compressor should be executed by an competent
engineer. Any poor wiring may cause electic shock or other electric fault.
Do not alter control parts or electric circuits attached to the electric box. The
compressor may be damaged due to malfunction of protection.
When opening the electric box door for routine maintenance or repairs, the main
power should be turned off to avoid any electric shock accident.

4.2.Wiring

The compressor is already wired internally. If opening the front door, you may find a hole for lead-in power cable on the bottom of the right side. Insert a wire into the hole for connection.
If open the front door, there is TB1. Please connect the power to it.
In case of wiring to the electric box, use the rubber bushing to protect the cable shearth and wire it to avoid of the shearth.
4.3.Power cable specifications
Use the EV or CV cable for 600V. For the thickness refer to page 24.

Rated current of main motor

Main motor cap.	AC220V	AC380V	AC440V
15(kW)	48A	28A	24A
18(kW)	58A	33A	29A
22(kW)	71A	41A	35A
27(kW)	87A	50A	43A
37(kW)	119A	69A	60A
55(kW)	178A	103A	89A
75(kW)	242A	140A	121A
110(kW)	356A	206A	178A
150(kW)	486A	281A	243A

Example of circuit-breaker wiring.

5. Routine checkpoints

Connecting to TBI of the compressor’s electric box.

If any impurities or dust is found inside when visually inspecting it, turn it off and clean it up with compressed air.

Black cable is power cable and the red/white/blue insulation tubes are inserted at the end of it. If the colors of insulation tubes are discolored to black, check the tightness of screws.

If screws are loosely tightened, it may generate heat, deteriorating cables and probably leading to a fire, so they should be maintained once a month.

Cable checkpoints.

6. Check motor insulation resistance

Take the following steps if insulation resistance is to be checked, for instance, operation of circuitbreaker. 1) Turn off the power of the compressor. 2) Set the voltage range of insulation resistance tester lower than 500V. 3) How to check the resistance; Loosen the bolt with (motor’s cable) and separate the cable from the terminal.

If it displays 10MΩ and over as the above, it is norma

Power Facilities of GRH3 air compressor

1.Cable thickness.
Since the compressor may not work properly depending on the power facility capacity and the thickness/length of the power cable and it may stop due to voltage dropping of control circuit or defective acceleration of the main motor, make sure to supply the power with the voltage dropping set within 5% of the rated power.

For the cable thickness of the lead-in cable, refer to the following table.

Main motor cap(kW)		15(18)	22(27)	37
Cable thickness	AC220	14	22	60
(mm2)	AC440	8	14	38
55	75	110	150	180
100	125	200	250	325
60	60	150	200	250

It is recommended that the cable length between a transformer/distribution board and the compressor is 100m and shorter; if longer than the length, the thickness may need reselecting.

2.Grounding specifications.

Grounding specifications are as follows.

Voltage	Grounding type	Grounding resistance
AC220A	Type 3	100Ω and lower
AC400A	Special type 3	10Ω and lower

3.Thickness of grounding cable (Bề dầy của dây nối đất)

Rated current	Cable thickness
20A and lower	2.0 and thicker
30A and lower	2.0 and thicker
50A and lower	3.5and thicker
100A and lower	5.5 and thicker
150A and lower	8.0 and thicker
200A and lower	14 and thicker
400A and lower	22 and thicker
600A and lower	38 and thicker

4. Circus breaker capacity.

The main power supply essentially needs a circuit breaker to avoid electric shock and protect the motor.
When selecting a breaker, refer to the following table.

Minh Phu provides maintenance and repair services for air compressors, in addition Minh Phu also provides spare parts for air compressors with high quality at reasonable prices. For further information, please contact (+84)919 23 28 26. Sincerely thank you for your interest and your trust of our service.