Instructions for the BASIC BCVA Rotary heat exchanger, Sizes

Transcription

1 Instructions for the BASIC BCVA Rotary heat exchanger, Sizes General The BCVA heat recovery unit is a rotary heat exchanger that offers high temperature efficiency. The heat exchanger operates with an efficiency of up to 82% on equal supply and exhaust flows. The efficiency is regulated by varying the rpm of the rotor. The BCVA can be supplied with a drive motor for constant speed, or a drive motor with speed control. The BCVA operates with horizontal flow. 1.1 Specification The version, size, etc. are specified in the delivery documents. 2. Installation 2.1 Mounting The BCVA heat exchangers are supplied with base beams as standard. It is important that the heat exchanger be positioned according to the labels on the side of its casing before it is connected to a duct or functional sections. The labels indicate the supply, exhaust, warm and cold sides. 2.2 Where to locate the filters The filters should preferably be located upstream of the rotor in the supply and the exhaust. If the exhaust fan is located at the pressure side of the rotor, a filter should be located upstream of the fan. 2.3 Inspection Always provide sufficient means for reaching the rotor for inspection and service from all four connections. If access cannot be gained from an adjacent functional section, a BCIA inspection section should be installed for this purpose. 2.4 Purging sector The BCVA heat exchanger is supplied with an adjustable purging sector as standard. On delivery, the sector is preset at max. and should be adjusted to the appropriate angle determined by the pressure differential across P 1 P 3 (see adjacent figure). The angle can be read from Table 1. If P 3 is greater than P 1, the purging sector should be omitted and a permanent cover plate should be fitted instead. This condition arises e.g. if the exhaust fan is upstream and the supply fan is downstream of the rotor. On placing an order with Swegon, specify if the purging sector is to be omitted The flow through a correctly adjusted purging sector is specified in Table 2. Exhaust Supplay Table 1 Pressure Angle differential, ( ) P 1 P 3 (Pa) Purging sector BCVA Table 2 BCVA Air flow through purging sector, (m 3 /s) Extract Outdoor Specifications are subject to alteration without notice. 1

2 2.5 Installation example - + Supply Exhaust 2.6 Commissioning Direction of rotation Before starting the heat exchanger, slip off its drive belt and run the motor briefly to check that it is rotating in the direction indicated by the arrow on the casing. If it is rotating in the wrong direction, move lead 2A to 2B or vice versa. Then check the operating current of the motor. All phases must be measured and checked against the data sheet Speed control With the rotor running at constant speed, the supply temperature cannot be kept constant at the preset value. On a rise in outdoor temperature, the indoor temperature can easily become too high. To restrict this undesirable temperature rise, the heat exchanger should be equipped with a speed controller. The efficiency of the heat exchanger varies with changes in the rotor speed. Varying the efficiency will keep the supply temperature constant at the preset value. If the indoor temperature is lower than the outdoor temperature, due to cooling for instance, running the rotor at full rpm will transfer cooling energy from the exhaust to the supply. The controller variably regulates the rotor speed between approx rpm to rpm depending on the size of heat exchanger. The cubicle containing logic equipment for speed control, purging operation, etc. is mounted on the drive motor Rotor in operation Make sure that the heat exchanger is running before the exhaust fan is started. Otherwise, dust is likely to collect in the passages of the rotor and clog them. 3. Maintenance 3.1 Cleaning Inspect the heat exchanger at least every six months and clean if necessary. Clean only by vacuum-cleaning with a soft nozzle or blowing with compressed. If more thorough cleaning is needed, get in touch with Swegon Service. The rotor bearings are maintenance-free. 3.2 Bristled seal While cleaning, check that there is no play between the rotor and the bristled seal. If the seal is worn, it should be replaced. If the bristled seal of the rotor has been removed and is to be reused, it is important that you refit it with the bristles leaning toward the direction of rotation. With use, the bristles namely bend toward the direction of rotation and later cannot be straightened. After you have replaced or adjusted the rotor seal, the heat exchanger should be run for 30 minutes to allow the seal to adapt to the rotor surface. Then measure the current consumed by the drive motor while it is operating and compare this figure with the rated current to make sure that the rotor is not running sluggishly. The max. permissible operating current is 80% of the rated current. An instrument that measures True RMS should be used. 4. Technical data 4.1 Operating principle The BCVA contains four rotors arranged diagonally in ps (as shown in the illustration below). EXTRACT AIR AVLUFT Viewed from above OUTDOOR UTELUFTAIR UTELUFT OUTDOOR AIR EXHAUST FRÅNLUFT AIR S U P P LY TILLUFT AIR Viewed from the side AVLUFT EXTRACT AIR UTELUFT OUTDOOR AIR FRÅNLUFT EXHAUST AIR TILLUFT S U P P LY AIR 2 Specifications are subject to alteration without notice.

3 4.2 Motor data Single phase, 220 V, 50 Hz Constant speed/variable speed control Number of Rated output Current A at Konden- BCVA motors per per motor rated output ser (W) 230 V unit µf Dimensions 75 A G 900 C E F O M L B BCVA A B C E F G L M O Wgt Baase beams: Standard Specifications are subject to alteration without notice. 3

4 Speed Control of the BCVA Rotary Heat Exchanger Motor. Variable Speed Control, Part No NB! There are 4. General The speed controller is mounted in a plastic enclosure with factoryfitted grommets for the various cables and a transparent cover. The controller is designed for installation inside the rotary heat exchanger casing and for operating a heat exchanger motor of Japan Servo manufacture, with tacho-generator. Output range: 25 70W. The controller variably regulates the speed of the heat exchanger motor between 70 and 1400 rpm. The standard transmission ratio will enable a rotor speed range from approx rpm to rpm depending on the size of heat exchanger. Performance is controlled by switching in and out of the "stand-by mode" and a control signal. The controller regulates the motor rpm in a capacity-linear manner in proportion to the input signal. Thus the speed change, per volt of signal change, will be slight for input signals less than 50% and great for those more than 50%. A rotation monitor and a purging operation function are incorporated into the controller. Alarms are indicated by a red LED and group alarms are initiated by means of alternating potential-free contact. Electrical installation (See the diagram below.) Power supply cable: 3 x 1.5, voltage: 230 V +/-10%, 50/60Hz. Control cable from the logic equipment cubicle for: Stand-by mode from potential-free contacts. Control signal: 0 10 V DC, 2 10 V DC, 0 20 ma or 4 20 ma for speed control. Group alarm function output, if specified. Separate alarm cable, if specified. The motor cable and rotation monitor sensor cable are factoryconnected if the controller is supplied with the heat exchanger. LON network cable, if specified. If the controller is to be connected to a master system across LONWorks, it must be ordered with the LON accessory. Setting The only setting that need be made is selecting the type of control signal. This can be set by means of the dip switch (see figure to the right) on the circuit board. 1 0 ON V DC V DC ma ma 1 1 Functions Stand-by mode: Closure between terminals 16 and 17 puts the controller on stand-by. The motor will start when the control signal exceeds 10%. Beyond that point, the speed will variably follow the control signal in a capacity-linear manner up to max. motor rpm. Start function: On closure of the stand-by mode contacts, the heat exchanger will operate at max. rpm for one minute and then adjust itself to the speed called for by the control signal. The start function will switch in regardless of whether or not a control signal is present. The purpose of this function is to counteract any shocking chill when the handling unit is started up. Control signal: The speed of the heat exchanger motor is controlled in a capacity-linear manner between min. and max speeds ( rpm). If the control signal is less than 10% of the max. input signal, the exchanger motor will not start. If the signal is at 10%, the motor will run at min. rpm. On a control signal of 100%, the motor will run at max. rpm. Purging operation: If the controller has been in the stand-by mode for 4 hours and during that time the control signal has not exceeded the 10% limit, the heat exchanger will start up and run at max. rpm for 1 minute to purge the rotor and rid its passages of contaminants. Rotation monitor: The rotation monitor sensor transmits an impulse to the controller every time the magnet on the heat exchanger rotor passes it. If the sensor has not sensed any impulse within 4 minutes while the control signal is above 10%, the heat exchanger motor will stop and the rotation monitor alarm will trip. Tacho-monitor: The controller senses the rpm of the heat exchanger rotor across the input from the tacho-generator mounted on the motor. If no impulses are obtained 10 seconds after the output voltage has reached max., the heat exchanger motor will stop and the tacho-monitor alarm will trip. To check the purging operation function: The purging operation function is similar to the start function; only the conditions required for start differ. The four-hour period cannot be overridden. Test the function by first switching of the stand-by mode and then switching it back on. 4 Specifications are subject to alteration without notice.

5 Alarms Rotation monitor: The alarm will trip after 4 minutes if no pulse has been received from the rotation monitor sensor during this period even though the control signal exceeds10%. The red LED (LD3) steadily shines and the yellow LED (LD4) flashes. The alarm relay is closed between terminals 9 and 11. Tacho-monitor: The alarm will trip if no pulse has been obtained from the tacho-generator 10 seconds after the output voltage has reached max. The red LED (LD3) steadily shines and the yellow LED (LD4) is off. The alarm relay is closed between terminals 9 and 11. LON-monitor: is active only if the LON-communication accessory is fitted. The red LED (LD3) steadily shines and the yellow LED (LD4) steadily shines. The alarm relay is closed between terminals 9 and 11. Power failure: None of the LEDs are lit. The alarm relay is closed between terminals 9 and 11. To reset the alarms The alarms can be reset by switching off the stand-by mode or power supply and then switching it back on. If the LON is connected, resetting can be done across the LON network. The LEDs Yellow LED: LD1. Is lit if the service pin for the LON has been activated. Used only if the LON-communication accessory is fitted. Green LED: LD2. Steadily shines while the controller is on standby. Closure between terminals 16 and 17. Red LED: LD3. Steadily shines if any alarm has tripped. Red LED in combination with yellow LED (LD4) indicates which alarm has tripped. Rotation monitor alarm: Red LED steadily shines yellow LED flashes. Tacho-monitor alarm: Red LED steadily shines yellow LED is off. LON alarm: Red LED steadily shines yellow LED steadily shines. Yellow LED: LD4. Steadily shines if the input signal is greater than 10% and the heat exchanger motor is to rotate. The LED will blink off 1 second and on, every time the magnet on the rotor passes the rotation monitor sensor. A yellow LED in combination with a red LED (LD3) indicates which alarm has tripped. Technical data Mains power supply V +/- 10%, 50/60 Hz Power supply fuse.... Min. 2AT, max. 10 AT Ambient temperature j C through +50 C Enclosure dimensions... W x H x D = 230 x 80 x 65 mm Degree of protection... IP 54 Alarm relay... Max. 250 V AC, 2 AT Fuse at motor output... Fine wire fuse 20 x 5 mm, 2 AT Rotation monitor sensor... Part. no Speed Control of the BCVA Rotary Heat Exchanger Motor Constant Speed, part no NB! There are 4. General The speed controller is located in a cubicle in the casing of the heat exchanger. The controller has a built-in thermostat that switches the rotary heat exchanger in and out. The temperature is registered in the outdoor intake section of the unit. The controller can be switched on standby and off by means of external, potential-free contact. It has a built-in rotation monitor and purging function. Group alarm output via alternating, potential-free contact. Electrical wiring (See the figure to right and below.) The terminal block is of spring-action type without any tightening screw. Connect to a 230 V AC ±10%, 50 Hz power supply. Connect the control cable from the logic equipment cubicle for: standby from potential-free contact, output group alarm function. Motor cable, sensor cable for the speed monitor and the temperature sensor cable are factory-wired. black red* brown t blue grey M grey yellow/green Supply 230V AC Setting Potentiometer P1 can be set for switching off the heat exchanger at the desired temperature. Factory setting:15 C. Potentiometer P2 can be set to the appropriate switch-on and switch-off differential. Factory setting: 0.25 C. Summary alarm *) By wrong rotation direction, shift red and blue wire brown blue Rotating guard sensor RR-G3 Start/Stopp temp. 0±30 0±90 C C P1 Drift Stopp Stop Temp.sensor P2 Service prep. Differential Differens 0,25±4,0 0.25±4.0 C C P2 P1 t C Specifications are subject to alteration without notice. 5

6 Functions Operational readiness: When the potential-free contacts are closed, the controller is ready for operation. If the contacts are opened, the motor will stop and the alarm and purging operation will be blocked. Control: The heat exchanger will be switched off if a rising outdoor temperature is registered by the temperature sensor in the outdoor intake section of the handling unit. The switch-off temperature can be reset on potentiometer P1. The difference between the switch-off and switch-on temperatures can be preset on potentio-meter P2. Rotation monitor: The controller receives a pulse every time the magnet on the rotor periphery passes the sensor. If the temperature is lower than the preset switch-off value (P1), and the pulses have ceased for more than 5 min., the controller will switch out the heat exchanger and an alarm will be initiated. Purging operation: If the controller has been ready for operation for 4 hours, and the outdoor temperature has been higher than the switch-off value that has been preset on P1, the heat exchanger will start up and run at full speed for one minute to purge the rotor surfaces clean of dust. To check the purging operation function: If the outdoor temperature is higher than the switch-off value preset on P1 at the time that the power supply is switched on, purging operation will start after 30 seconds. Alarms Rotation monitor: An alarm with flashing red LED (lit 75% of one second) will appear if pulses from the rotation monitor sensor cease for more than 5 minutes. The alarm relay will alternate. Sensor error: An alarm with flashing red LED (lit 25% of one second) if pulse transmission is interrupted or if the conductor from the sensor is short-circuited. Power failure: The alarm relay alternates. To reset alarms: Alarms can be reset by opening and closing the standby contacts or by briefly opening the mains power supply. LEDs Green LED: Steadily shines when the unit is ready for operation. Yellow LED: Steadily shines if the outdoor temperature is lower than the switch-off value preset on potentiometer P1. The LED is off for one second every time the rotation monitor sensor receives an impulse. Red LED: Flashes (lit 75% of one second) if the thermostat calls for rotor operation and pulses from the rotation monitor sensor cease for more than 5 minutes. Flashes (lit 25% of one second) if pulse transmission is interrupted or if the conductor from the sensor is shortcircuited. Technical data mains power supply V AC ±10%, 50 Hz Fuse - power supply...10a Operating temperature till +50 C Dimensions of the enclosure...b x H x D = 230 x 80 x 65 mm Degree of protection...ip54 Alarm relay...potential-free, alternating 250 V AC 10A Fuse motor output... Fine-wire fuse, 20 x 5 mm, 1.25 AT 6 Specifications are subject to alteration without notice.