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).

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.

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.

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.

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.

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.

The compressors are end of life since more than 20 years. All genuine first party replacement part stocks are empty. Please consider to upgrade to a newer compressor.

You can find all compatible controllers to your compressor in the compressors data sheet. All compressor data sheets are available in our Product Selector.

Re-charge or replace the 12 V battery that supplies the compressor with energy. Batteries degrade over time and can be discharged after some time without usage.