Hermetic Compressors for Refrigeration

The amount of oil we charge our compressors with can be found in the data sheet of the individual compressor. The data sheets can be found and downloaded via the Data Sheet Selector on our website.

More information can be found in our catalogs which contain an introductory section with some information on use, oil type, starting equipment, and application limits for the Secop compressors.

Compressor oils used by Secop include:

For R134a compressors:

• PL and TL: 15 cSt POE oil
• NL and FR: 19 cSt POE oil
• SC: 22 cSt POE oil

Secop has MSDS sheets for the original oil that will be handed out to customers on request. Please contact your local Secop company.

Important factors determining the lifetime of hermetic compressors are:

• System dimensioning and system lifetime
• System temperature, esp. valve and winding temperature
• System pressure
• Purity of system components
• Quality of refrigerant and oil
• Lifetime of other system components
• Quality of main power supply (cutouts, voltage drops, etc.)
• Application duty cycle

In a typical application where the compressor is used within the specified limits given in the actual product literature, a lifetime of 10–15 years can be expected as a rule of thumb.

The lifetime of a compressor used in a household application may be longer than the lifetime in light commercial application.

Yes, we publish our compressor performance data according to the ARI standard 540-91 and EN 12900.

We will gladly provide data for specific compressors if requested. Please contact us via our contact form. 

The most relevant factors are:

• Combination of components in the cooling system (layout and installation)
• Pulsations and turbulences in the refrigerant gas related to the specific system
• Actual level of system insulation
• Function of machine compartment
• Actual system vibration prevention
• Suction and/or pressure mufflers 

The Secop compressors are extremely low noised compared to the average products from the competition.

Horsepower or hp is a historic designation for the engine performance. There is no official standard relation to refrigerating capacity. All manufacturers have developed their own formula. Therefore, the data stated in hp by different manufacturers cannot be compared.

Furthermore, a capacity given in hp is dependent on the application range of the compressor, i.e. 1 hp of an air-conditioning compressor is different from 1 hp of a LBP compressor.

If the capacity in W or BTU/h at given conditions is known, this should be preferred for comparison.

Secop compressors are not cooled by suction gas but with the oil circulating inside the compressor housing. The housing then transports the heat to the surroundings.

Serial numbers were introduced in July 2004. The serial number is individual to each single compressor. There is no relation between serial number and production date, shipment day, or the like. The serial number has been introduced to help our customers use the individual compressor serial number in the documentation for their appliances. The production date can still be found in the stamped code on the compressor housing. 

What information does the date stamp on the compressor housing provide?

Secop compressors have a manufacturing date code stamp or a needle print on the housing. The content of the coding is set in two lines.

For more information, see Product Bulletin: Date Code Format, Country of Origin, and Labels
 

Please refer to our brochure: Key to Compressor Type Designation

The most relevant factors are:

• Combination of components in the cooling system (layout and installation)
• Pulsations and turbulences in the refrigerant gas related to the specific system
• Actual level of system insulation
• Function of machine compartment
• Actual system vibration prevention
• Suction and/or pressure mufflers 

We don't have the data sheets of our older compressor and condensing unit types on our website, but we will gladly send you the documentation by mail or e-mail on request.

The PTC protects the start winding by switching it off.

A compressor can be started using a PTC if the appliance has a standstill period of a minimum period of seven minutes in order to ensure pressure equalization via the capillary tube.

Generally, the compressor should be still okay even if the PTC starting device burns out – we recommend using a new PTC instead.

The nominal values for the main winding and for the start winding at a temperature of 25°C are stated in the data sheet. Depending on the actual ambient temperature, this nominal value has to be corrected by a factor from the following table.

Example: For the NL7CNK compressor, the value given in the data sheet is 14.7 Ohm @ 25°C. If your ambient temperature is 40°C, you have to multiply this by 1.058 as declared in the table. So your resistance would be 1.058 x 14.7 Ohm = 15.6 Ohm. Please note that these values apply only if the resistance is measured directly at the stator – you should include a tolerance of about +/- 10%.

The main advantage of the ePTC solution is the easy way of saving energy in existing and future fridge and freezer designs.

This is due to the following factors:

• Reduction of 2 W in power consumption
• Full PTC protection of start winding
• Can be operated with a run capacitor
• Silent operation
• Short recovery time
• Compatibility to all Secop 103N PTC starters

 In special cases, an ePTC can replace a PTC/run capacitor combination.

In this example, the capacitor can operate at 220 V AC for a maximum time of 1.7% within three minutes. More exactly, this means the capacitor should be operated for a maximum of 3.1 seconds and afterwards be turned off for 176.9 seconds. At 280 V AC, the capacitor can be used for 0.3 seconds in a period of one minute.

Yes, that is possible. The voltage rating of all capacitors must be the same as, or higher than, the specified voltage.

For safety reasons, Secop only distributes run capacitors of safety class P2 (with aluminum housing) instead of safety class P0 (with plastic housing) with its compressors. A P0 run capacitor is normally not used by, for example, German manufacturers because of safety and insurance reasons.

On the other hand, we know that P0 run capacitors are used by several manufacturers elsewhere. If a P0 run capacitor is used, it is very important to follow the instructions from the supplier regarding safety conception to prevent any fire in case the flammable capacitor, which is not protected, fails – for example, the distance to flammable parts should be at least 100 mm or the capacitor should be encapsulated.

So when technical matters are ok on the P0 capacitor we cannot see why it should not be operated with a Secop compressor. Also, please consider that the Secop run capacitor holder probably will not fit the capacitor. Compact installation including earth connection cannot be ensured because it cannot be installed directly on the compressing housing.

Generally no, it cannot.

The Secop Engineering department has selected optimized starting equipment for each compressor which meets the requirements and specifications. We, therefore, strongly advise using only the starting equipment that is recommended by Secop.

Especially when using starting relays, the cut-in and cutout current values have to match the motor requirements precisely. A wrong relay can destroy the motor or the start capacitor and cause severe safety problems.

When we state a voltage range of 198 V to 254 V in our catalogs, it means that the compressor can both run and start at voltages within this range.

Example: A cooler from 1977 is equipped with a PW7.5K14 compressor. For several months, the compressor ran longer and longer and finally worked continuously. Since the thermostat is operational, it is probable that the compressor has reached the end of its lifecycle. Is there any appropriate substitute?

No, Secop will does not recommend substitutes for failing old devices. If a compressor that has been used in an appliance for ten or more years finally fails, replacing the compressor is not recommended, even if it is technically feasible. After ten or more years of use, the insulation and the sealing of a refrigerator and freezer are used up. This would lead to significantly increased energy consumption.

Furthermore, the refrigerant R12 is no longer allowed in most countries. Replacing it with another refrigerant will become quite expensive.

The sensible recommendation is to buy a new appliance.

The positions in which each compressor is allowed to be shipped are stated in the Product Bulletin – Shipment of Refrigeration Appliances in the Horizontal Position. If the unit has been shipped in the correct position in accordance with the Technical Information, we recommend waiting 30 minutes before switching on the refrigerator.

The positions in which each compressor is allowed to be put are stated in the Product Bulletin – Shipment of Refrigeration Appliances in the Horizontal Position. 

 If the unit has been shipped in the correct position in accordance with the Technical Information, we recommend waiting 30 minutes before switching on the refrigerator.

There are two main differences between the tropical compressor and the corresponding standard compressor:

• All tropical compressors can be operated at a maximum ambient temperature of 43°C while most standard compressors are designed to work at temperatures of up to 38°C.
• While the tropical compressors can be operated at a voltage range from 187 V to 254 V, the corresponding standard compressors have a smaller range of 198 V to 254V.

These factors require the tropical compressors to be equipped with a stronger motor which slightly decreases the COP. 

The crankcase heater is a heating element which is placed around the compressor to heat the compressor oil during standstill periods.

Depending on temperature and pressure, the oil in the compressor absorbs bigger or smaller amounts of refrigerant. During standstill periods, the oil level in the compressor rises due to the refrigerant solution in the oil. On start-up of the compressor, the pressure on the oil is reduced and the refrigerant dissolves in the form of vapor. This causes the oil to foam. The foam can even reach the compressor suction tube and the cylinder, which can cause the hydraulic pressure in the compressor cylinder. This can result in damaged valves and gaskets.

Especially during the first start and defrost, when the compressor is colder than the evaporator, the oil absorbs a lot of refrigerant. By using a crankcase heater during standstill periods, the compressor can be maintained at a steady temperature so that only a small amount of refrigerant is absorbed by the oil. When starting it for the first time, and in cases where refrigeration systems use a large charge, a crankcase heater must be cut in two to three hours before starting the compressor.There are two cases where a crankcase heater is recommended:

1. Properly using a crankcase heater can reduce the risk of liquid hammer in cases where the maximum refrigerant charge as given in the compressor's data sheet cannot be complied with. If a crankcase heater is used, the maximum refrigerant charge can be increased by up to 70%.
2. If the compressor is located where it may get colder than the evaporator, it is always recommended to use a crankcase heater. In the case of extremely low ambient temperatures, oil viscosity can become relatively high. If this causes starting problems, it may be advisable to use a crankcase heater even on domestic appliances.

Yes there is. Please check our Product Selector for available types.

The most relevant factors are:

• combination of components in the cooling system (layout and installation)
• pulsations and turbulences in the refrigerant gas related to the specific system
• actual level of system insulation
• fx of machine compartment
• actual system vibration prevention
• suction and/or pressure mufflers