Frequently Asked Questions Secop FAQ

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

For R600a compressors:

• TL: 7 cSt or 10 cSt mineral oil
• NL: 15 cSt mineral oil

For R404A compressors:

• All types use 32 cSt POE oil.

All refrigeration oil types used by Secop do not contain any additives; only antioxidants are allowed.

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.

The position of the motor protection switch on Secop compressors can be determined from the second letter of the compressor's nomination for the P/T/D/N and F-series. "T", "F", or "LV" indicate an external protector. "L" and "R" indicate an internal protector. 

For the SC compressors, please check the data sheet of the individual compressor. For most types, the protector is internal. Only some 115 V/60 Hz types are equipped with an external protector. In these cases, the protector is shown as a separate part in the figure (f) and listed in the list of accessories in the data sheet, too.

For more information on the designations of Secop compressors, see the page "Key to Compressor Type Designation" from our website.

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 puts a date stamp on each compressor. Two lines of data are stamped into the housing above or just to the right of the paper label.

The first line states the model designation and the code number, for example, L-4CL-2071:

• L = Last letter (or last two letters) of the compressor type
• 4CL = Nominal displacement
• 2071 = 4 last digits in the code No

In 2002, Secop started to introduce new coding consisting of two lines, for example:

• H4485C
• 051D11R

First line:

• H4485 = Compressor type information (102H4485 = H4485)
• C = Internal Secop Code

Second line:

• 05 = Production week
• 1 = Production year
• D = Production day (A = Monday, B = Tuesday, etc.)
• 11 = Production hour 00 to 23 or shift code -1, -2, -3
• R = Secop internal production location code

• A-G, U = Germany
• A until week 50/2005
• D until week 35/2006
• U until week 08/2010

• K-N = Slovenia
• L until week 34/2011

• A, D, L, R, U Slovakia
• A from week 01/2006
• D from week 38/2006
• L from week 44/2011
• R from week 01/2005
• U from week 12/2010

• R-S Mexico
• R up to week 27/2004

• W to Z China

For more information, view the product bulletin Date Code Format & Country of Origin from our website.

Two lines of data are stamped into the housing above or just to the right of the paper label. The first line states the model designation and the code number, for example, L-4CL-2071:

• L = Last letter (or last two letters) of the compressor type
• 4CL = Nominal displacement
• 2071 = 4 last digits in the code no.

With this information, please contact your local Secop representative who will further assist you.

The type code consists of separate single letters.

The first letter stands for the compressor series ("BD", "P", "D", "T", "N", "F", "S", or "G").

The second letter indicates the protector location:

• "L", "R", and "C" = internal protector
• "T", "F", or "LV" = external protector

The third letter gives the optimization level

• E = Energy-optimized
• S = Semi-direct intake 
• Y = Highly energy-optimized 
• X = Very highly energy-optimized

The number denotes the displacement in ccm. For P and BD compressor types, it gives the cooling capacity in W at rating point.

The letter that follows gives the application range and the refrigerant.

The next letter denotes the starting characteristics:

• " " = Universal
• "K" = LST characteristics (capillary) 
• "X" = HST characteristics (expansion valve)

The last digit means the generation in development:

• " " = 1st generation
• "2" = 2nd generation, etc.

For further information, please refer to the "Key to Compressor Type Designation" on our website.

Until 2010, Secop was known as Danfoss Compressors GmbH and belonged to the Danfoss Refrigeration & Air Conditioning Division of Danfoss GmbH from Nordborg, Denmark. In November 2010, the company was acquired by the Munich-based (Germany) based investment group AURELIUS AG. The takeover included all business activities in Germany, China, Slovenia, and Slovakia and all approx. 3,000 employees.

Secop remains a close, long-term partner of the Danfoss Group and will continue to sell major parts of its products and solutions through the Danfoss Group and its sales companies. In the course of the acquisition, Danfoss Compressors was renamed and completely rebranded as Secop GmbH. The company headquarters are located in Flensburg, Germany.

The R&D team developed a new technological platform called System Effective Coefficient Of Performance (S.E.C.O.P.) and combined with the external rotor motor technique, they had the basis for the XV compressor. Later this project name was chosen as the name for the new compnay.

In April 2013, Secop acquired the insolvent company ACC Austria GmbH in Fürstenfeld, Austria, with its 700 employees. As part of the regulatory approval process, the referral process was completed by the European Commission in September 2013.

With more than 60 years of experience in compressor technology and with our highly committed employees, our focus is to develop and produce advanced compressor technologies which achieve standard-setting performance for leading products and businesses around the world.

The compressors are charged with ester oil (POE) with a viscosity of 15 cSt.

Alternative oils that can be used in a service situation are:

• Emkarate RL15H, manufactured by Uniqema
• Mobil EAL Arctic, manufactured by Mobil Chemicals
• CP2915AS, manufactured by CPI

The BD solar compressors can be connected to a solar panel without the use of any additional electronics or the use of a battery. The BD Solar compressor electronic unit includes an option to adapt to the voltage range of solar modules (9.6 V to 31.5 V). To achieve this, a resistor of 220 Ohm has to be connected between terminal C and P. The electronic unit also includes the AEO (adaptive energy optimizer) option.  

Yes, they are. Please refer to these code numbers:

• BD35F: Code no. 101Z0203. Suction and process port 1/4” and discharge 3/16”
• BD50F: Code no. 101Z0204. Suction and process port 1/4” and discharge 3/16”

No, using R404A with the BD compressors in their current design is not recommended or supported by Secop.

The specifications of the motor as well as of the oil prohibit the use of R404a in these compressors.

The power consumption in general and the starting current needed are very high using R404A. That will make the start of the compressor questionable. Even if the compressor was used in low-temperature applications (LBP) only, it would not be able to make the pull down.

Generally, the customer can use the LED for failure detection. Errors are indicated by the failure LED. For the details, please refer to the instructions which can be found on our website. Additionally the following can be checked:

If the compressor does not start at all the first time:

• Check connections on compressor and back of battery.
• Check for loose connections in plug or leads. 
• Check poles on the battery (verdigris on poles or contacts?).
• Check correct setting of standard or resistor changed battery voltage protection (see instructions, wiring diagram and description).
• Check whether battery voltage is within the battery protection limits.
• Check thermostat and connection to ports C and T.
• Check fuse and polarity: Has the fuse blown because of wrong polarity? If so, change the fuse and try again with the correct polarity.
• Test resistance between all three current lead-in pins? If the value between all three pins is approximately the same, the motor is most likely still okay. Otherwise, the compressor must be changed and investigated closer by Secop.
• If the compressor is so far okay and no external faults have been detected, the electronics have to be closer investigated by Secop. 
• If the compressor starts but operates only for a short time: the problem can be a dimensioning problem of the cooling circuit (evaporator or condenser size, charge). 
• If the compressor stops approximately 2 seconds after starting the fan (2 flashes on LED), then the fan is overloading the electronics and the fan fault has to be solved or a smaller fan has to be used. In this case, solve the fan fault or use a smaller fan. 

For further information, refer to our page Electronic Units Instructions.

Whether a fan is necessary or static cooling is sufficient depends on the application the compressor is used for. If a fan is required, the 12 V as well as the 24 V direct current systems have to be equipped with a 12 V fan.

A 692 Ohm non-standard resistor is recommended for the 3,000 RPM setting of the BD35F and BD50F compressors. Can a standard resistor of 680 Ohm be used instead?

If you use a 680 Ohm resistor in the control (thermostat) circuit, the motor speed will just be a little less than 3,000 rpm. However, the difference between the two resistance values is so small that no difference in performance would be noticeable in practice.

For more information on the resistance as well as the electronic unit, please view the page "Electronic Units Instructions" on our website.

The maximum current is 4A. If the current is higher, the compressor will not stop. It will just not allow higher consumption. In practice this can lead to reduced speed. In worst case, the compressor will revert to its minimal speed of 1850 rpm. Please also check the data sheet which can be found on the page Electronic Units Instructions on our website.

Depending on the selected setting, the controller of the compressor's motor has a cutoff voltage of 9.6 V to 10.4 V on a 12 V power supply. On a 24 V power supply, the cutoff value is 21.3 V - 22.8 V (for details refer to table "Optional battery protection settings" in the Instructions of those units). The starting current is approximately 14 A.

If the compressor has not reached the minimum speed or the minimum voltage is not available 1–2 seconds after starting, it will be switched off again.

Because the undervoltage of a ripple voltage supply is defined by the minimum value, the compressor's electronics are not suitable for the operation with a battery charging station or not stabilized power supplies. The power supply must be able to handle a current of up to 7.5 A and a starting current of up to ca. 14 A in order not to reach the minimum voltage, even if there are ripples. Since normally the battery would buffer this, connecting a small battery, for example, of a lawn mower or a motorcycle, should be sufficient to solve this problem.

Secop does not stock any AC/DC converters, nor do we recommend any. But since those converters are widely available, it should be rather easy to buy a unit anywhere.

A simple device like a traditional battery charger is sufficient if the converter is connected to a battery. The compressor will then be powered by the battery. An output power of about 70 W (6 A) will be needed.
Running the compressor directly from the AC/DC converter is more complicated and only possible with the DC compressors BD35F or BD50F. The converter output voltage needs to be an approximate DC with a maximum ripple of 0.5 V peak to peak. Furthermore, the unit must be able to yield a current of 14 A for 1 second at a minimum voltage of about 11 V.

We strongly recommend running the compressor with a battery since this will ensure a stable refrigeration system operation.

For more information on the electronic unit, please refer to our website.

On 50 Hz supply, the compressors nominally run at 2,900 rpm while at 60 Hz the nominal speed is 3,450 rpm.

The diode should be rated 10 mA. The electronic unit will send a flashing current signal of approx. 4 mA constantly into the circuit in case of a fault.

No, that is not advisable.

BD compressors are designed to be operated on a DC power supply. To run the compressor, the electric equipment needs to generate the magnetic field that basically turns the rotor. If the compressor is used without an electronic unit, it can be destroyed. For more information on the electronic unit, please see the page Electronic Units Instructions on our website.

Yes, they have:

• Australia and New Zealand: C-tick mark. AS/NZS 4251.1
• Automotive market: e mark according to 95/54/EC
• VDE in combination with 101N0500
• USA: UL file no SA 3693

The term "ampacity" is a combination of "amperage" and "capacity".

The formula for the calculation of the ampacity is: RLA (rated load amps) of the compressor added to FLA (full load amps) of the fan multiplied with 1.25 (safety factor).

The ampacity defines the maximum current that can occur when the compressor is running at the highest specified load and a higher voltage than given.

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.

No. Secop does not endorse the use of any substance except the refrigerant and the oil designed for use in the specific compressor.

No, it cannot.

All Secop hermetic compressors use motor windings of enamel copper wire, and some other small parts of copper or copper alloys. The copper will be attacked by ammonia, so the compressors will certainly be damaged.
All materials used for the internal parts of Secop compressors are only tested for chemical compatibility with the oils and refrigerants they are made for. Changing the oil, maybe even changing the producer of the oil, might lead to problems. 

Ammonia generally is not used in small hermetic systems because ammonia develops very high temperatures when compressed.

No, we don't.

Secop compressors are available for R12, R22, R134a, R290, R404A, R407C, R502, R507, or R600a applications. We have no experience with compressors used with other refrigerants or used in cascade applications at very low temperatures. We know that some customers use the compressors with other refrigerants, but we have not been involved in any testing or approval for such applications and/or system layouts.

If a compressor is used for any such special application (at one's own risk), it is recommended that the load conditions do not exceed the equal maximum load conditions of the refrigerant the compressor is designed for. General information on the operating conditions can be found in the relevant catalog, more specific data is available in the data sheet of the compressor.

 

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.

t/°C	t/°F	Factor
10	50	0.942
15	59	0.961
20	68	0.981
25	77	1.000
30	86	1.019
35	95	1.039
40	104	1.058
45	113	1.077
50	122	1.096

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. 

Yes, there is. A 55W crankcase heater is available for the SC compressors. The code no. is 192H2096.

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

The use of R407C with the FR6DL has not officially been approved or tested. Only the SC-DL compressor types are approved for use with R407C.

If the FR6DL compressor is to be used with R407C, Secop recommends to keep it within the R404A operating conditions (as provided in the data sheet). The two refrigerants have rather similar thermodynamic properties. Please note that the unapproved use of the FR6DL with R407C is at the user's own risk. 

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 

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.

t/°C	t/°F	Factor
10	50	0.942
15	59	0.961
20	68	0.981
25	77	1.000
30	86	1.019
35	95	1.039
40	104	1.058
45	113	1.077
50	122	1.096

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%.

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.

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.