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THE
SMART SPEED CONTROL |
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Part Number E52150
The Smart
Speed Control is an electronic device with a remote panel connected to
the BD35 or BD50 controller with a multi-core
cable. The remote panel can be flush-mounted (requires a 2-5/8"x 1-7/8" cut-out) or mounted in its own housing. The housing can be used for protection of the rear of the panel when it is flush mounted. |
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The panel has a six speed bar graph to display the current speed setting, together with "Auto" & "Manual" LED's to indicate in which mode the system is operating. The appropriate "Auto" or "Manual" LED will be green when the compressor is running & will change to orange when the thermostat is "off" & the compressor is idle. A push-button is provided to change the operating mode, & also to enable speed selection in the "Manual" mode. There is a separate LED that will flash a fault code in the event of a malfunction, and a power terminal multiplier to accommodate multiple connections to the + ve & - ve terminals. The SSC is connected to the system in addition to the Danfoss controller & a thermostat & does not replace these items. |
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PRINCIPLES
OF OPERATION
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| The Danfoss BD35 & BD50 compressors are internally driven by what are basically 3 phase motors that can be run at any speed between 2000 rpm & 3500 rpm depending on the frequency of the signal applied to the windings. The Danfoss controller that is attached to the compressor housing converts the incoming 12 or 24 volt dc power into the modified dc that is needed to run the motor, & the speed of the motor is determined by the value of a resistor connected in series with the thermostat lead. All but the smallest Frigoboat systems are supplied with a 4-Speed selector panel that mounts on the controller, & this can stay in situ for use in the case of a malfunction with the SSC. AH & AV models have a "Master Control" that incorporates a speed choice, & this too remains connected when the SSC is installed. Other manufacturers may mount resistors somewhere in the thermostat circuit to force the compressor to run at a speed predetermined for the size & type of evaporator & condenser used. This avoids over-capacity & component stress & also reduces current draw to an safer, more acceptable level, but is not easily adjustable. If a thermostat is connected directly to the controller, without any resistor, the compressor will run at the slowest speed, 2000 rpm. | ||||||
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FRIGOBOAT
SMART SPEED CONTROLLER (SSC)
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| The overall efficiency of a refrigeration system is determined by its Coefficient Of Performance (COP). The higher the COP the greater the efficiency of the system, & the highest COP is achieved by running the compressor at the slowest possible speed for the longest possible time. Also, by altering the speed of the compressor, the system capacity can be adjusted to match the application & conditions, & the current draw kept to an acceptable & safe level. | ||||||
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MODES
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AUTO
MODE |
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FEATURES
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AUTOMATIC SPEED SELECTION The "Automatic Speed Selection" feature ensures that the most efficient compressor speed is engaged dependent on the prevailing conditions as described above. SAFETY START The "Safety Start" feature ensures that when power is supplied & the system is started initially, under warm box conditions, the SSC will start in "Auto" mode at a medium speed to protect the electronics from being overloaded. After a short period of time the speed will be increased incrementally until the maximum speed is reached or the thermostat turns the system off, & then continue the "Auto" sequence for the subsequent cycles. If the thermostat is off when power is supplied to the system (i.e. box is cold), the SSC will start in the "Auto" mode at maximum speed & then continue the "Auto" sequence for the subsequent cycles. BOX RESTOCKING The "Box Restocking" feature provides a means to activate the maximum capacity of the system whenever warm goods are stocked into a cold box or rapid cooling is required. This is accomplished by switching to "Manual", selecting the highest speed, & then reverting to "Auto" mode. FAULT DIAGNOSIS The "Fault Diagnostic" feature will flash the "Fault" LED up to 5 times every 5 seconds in the case of one of five fault conditions |
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INSTALLATION
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| The SSC is designed to be installed on Frigoboat systems, & some wiring & other changes may have to be made for installation to other manufacturers systems, where any resistors connected in series with the thermostat will need to be removed. The SSC will only perform as designed if the thermostat is a mechanical model, & without a resistor in the circuit. The electrical connections should be made in accordance with the wiring diagram, &, upon completion, all connections should be inspected for integrity & safety. If a Frigoboat 4-Speed selector board is fitted or a "Master Control" connected to the system (AV & AH models) these can remain in place & the "C" & "T" leads of the SSC are then connected to the "C" & "2000" terminals respectfully, & not directly to the Danfoss controller. The SSC remote panel should be mounted in a convenient location & the rear of the panel protected from physical & water damage. | ||||||
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OPERATION
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| On initial power-up, the SSC will start in the "Auto" mode & with the "Safety Start" feature enabled. If the power is not interrupted & the push-button not depressed, the system will continue in the "Auto" mode to find the most efficient running speed after a few cycles. Depressing the push-button for one second or longer changes the mode from "Auto" to "Manual" or vice versa. When in the "Manual" mode, depressing the push-button for less than one second changes the speed setting in ascending order, ( from speed 6 it will revert to speed 1) . When the mode is changed from "Manual" to "Auto", the "Auto" sequence will be started at the speed that was set in the "Manual" mode. When the "Box Restocking" feature is required, switching to the "Manual" mode, setting the speed to the highest setting, & then changing back to "Auto" mode restarts the "Auto" sequence at maximum capacity. | ||||||
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