DC Generator

• The 972 gas engine is derived from a diesel engine block. The injectors are removed and a gas carburettor, spark plugs and ignition are added along with reducing the compression ratio. The conversion and manufacturing is performed by Kubota. The heavy-duty diesel type engine block, bearings, crankshaft, cylinder, and pistons provide a very reliable and long life generator.
• There are 4 heavy duty bearings supporting the crankshaft in the 972 engine as opposed to 2 light duty aluminium bearings  typical of our competitors’ generators.

• In cold climates the water cooled engine can use its thermostat to regulate combustion temperatures improving fuel efficiency and reducing engine maintenance. Typical air cooled generator engines do not have the ability to regulate combustion  temperatures.
• In hot and cold weather extremes the water cooled engine provides lower oil maintenance than the air cooled.
• In hot weather the water cooled engine’s oil temperature is typically under 125˚C whereas air cooled engines typically operate at temperatures above 150˚C reducing the service life of the oil. In cold weather the oil temperatures can be too low to remove the absorbed water from the combustion process, this also reduces oil service life.
• The 972 has a larger oil capacity in the oil pan than conventional air cooled engines, reducing oil checks and changes.
• The 972 can make use of Polar’s Electric Radiator option saving 10% to 15% in fuel.

• For low noise requirements the water cooled engine can take advantage of its fluid lined cylinders for noise reduction at the source
• Sound traps inside the enclosure are more effective with water cooled engines than air cooled.
• Polar offers an electric radiator option that incorporates electrically driven fans that produce lower noise than belt or direct driven engine fans. The electric radiator can be mounted external to the sound attenuating enclosure allowing a more efficient means of sound attenuation.

• The air cooled engine disperses the heat all over the shelter or enclosure, additional fans are typically required to scavenge the hot air and remove it from the enclosure. The fluid cooled generator can make use of the radiator and fan to direct the heat away from the enclosure. Enclosures for the 8220K-972 typically operates at 4-7˚C over the ambient air temperature. Typical air cooled generators operate at 16-33˚C over ambient, which greatly lowers the reliability of the batteries and control electronics.
• For sites with very cold weather conditions the problem with air cooled generators is that the air flow volume is not easily controllable and too much cold air is brought into the shelter. The 8220K-972 can have is radiator  installed exterior to the shelter, so only a minimum volume of air needs to enter the shelter.
• Too much air flow into the shelter can be a maintenance problem in dusty and sandy environments, another advantage to installing the radiator outside the shelter.
• In hot weather if the electric radiator is installed inside the shelter the fans can cool the shelter without requiring additional fans. This is an advantage in removing the heat from the engine after it cycled off (thermal lag).

DC Air Conditioner

1. Unreliable grid or generator power using 1 standard AC air conditioner with the grid available or when the generator is loading the batteries. One DC powered air conditioner in case of a grid power black-out or generator off (batteries loaded) Shelter 24 C-30C. For a generator powered BTS station the running time of the genset will go down by 50-60%.
2. Solar or wind powered. Two DC Aircon units in 1+1 configuration switched by inbuilt PLC Remote alarms /logging available. Shelter temp 24-30C. The low consumption DC Airco units use 2-3 less energy than a normal AC on an inverter. Power consumption 600 watt.
3. Grid or generator powered or solar/wind powered . Using a powerful DC Aircon free cooling for the shelter and a small DC Airco battery cooler for the outdoor battery cabinet to keep the batteries at 24 C for a long lifespan. Depending on the load the shelter temperature may go up 5 to 10C above the outdoor ambient. Power consumption 200 + 400 watt
4. Grid or generator powered or solar/wind powered . Using a powerful DC Aircon free cooling for the shelter and a small DC Airco battery cooler for the indoor battery cabinet to keep the batteries at 24 C for a long lifespan. (batteries compartment insulated from equipment with sandwich panel). Depending on the load the shelter temperature may go up 5 to 10C above the outdoor ambient.
    Power consumption 200+400 Watt. The battery cooler may be installed indoor or outdoor. If installed indoor the extra heat load is approx. 600 Watt to be removed with the free cooling.

1. Grid generator or solar wind powered using the energy efficient DC 10.000HA dc powered Air conditioners in warm weather and the free cooling at night and winter. Switching set point can be set on DC10.000HA PLC. Consumption 200 or 600 Watt. If you choose 30 C indoor ambient as switching point the outdoor temperature must be below 25C with 3,4 KW load and below 20C with a 6,8 kW
   load.
2. Using a powerful DC Aircon free cooling for the shelter and a small DC Aircon battery cooler for the indoor battery cabinet to keep the batteries at 24 C for a long lifespan. (batteries compartment insulated from equipment with sandwich panel) Depending on the load the shelter temperature may go up 5 to 10C above the outdoor ambient. Consumption 200 W + 400W.
3. The battery cooler may be installed indoor or outdoor. If installed indoor the extra heat load is approx. 600 watt – to be removed with the free cooling.
4. Using a powerful DC Aircon free cooling for the shelter . Depending on the load the shelter temperature may go up 5 to 10 C above the outdoor ambient. ( 5 C with max 3,4 kW load and 10 C with max 6,8 kW load) Consumption 200Watt max.