Series Ma - Operating & Maintanance Instructions

MA series OMI

	OPERATION AND MAINTENANCE INSTRUCTIONS FOR MA SERIES INDUCED DRAFT COUNTERFLOW COOLING TOWER. 1. PRE START UP: Before a Lakeside Cooling Tower is started up for the first time, or after a long shut down, it should be cleaned and inspected. When a new installation is involved with supervision of a Lakeside field supervisor, the following steps have already been carried out as part of the cooling tower installation. The erection instructions provided with the field assembly cooling towers also include these following instructions. Therefore, under these circumstances, the Pre Start procedure instructions need only be followed again, if the cooling tower should be shut down at a later stage. DANGER – TURN OFF, TAG AND LOCK FAN MOTOR SWITCHES. Inspect the cooling tower to see that nozzles, fill media and cold water basin are free of debris of foreign matter. If any foreign matter is present, wash it into cold water basin with the use of a high-pressure water spray gun. Drain the water away through the drain connection in the cold water basin and manually remove any debris left in the cold water basin – particularly from the suction screen. Check the fan for free rotation and proper tip clearance in the fan cylinder. Inspect to see that all blades are true to prevent unbalanced operation. Check to see that the float valve is operating properly and fill the cold water basin with water right up to the bottom of the overflow pipe in the cold water basin. Primes the circulating water pumps (prime it manually, if necessary, and allow it to run until the connected piping system is full of water. It may be necessary to use a supplementary supply of water to that supplied by the float valve at this stage, if the connected piping system requires a lot of water to fill it. The water, which fills the piping system, must come from the cold water basin and if the quantity required is great, then the level of water in the cold water basin could drop to a point where the pump cavitates. The addition of supplementary water to assist the float valve at this stage, and under these circumstances, will prevent pump cavitation. When the as a whole has settled down, eg. the whole water circulating system has been operating satisfactorily for ten minutes, shut off the pump. The level of water in the cold waterbasin will rise and some water may run to waste via the overflow pipe. This is to be expected, particularly if supplementary water has been added. During this ten-minute period, the pump should be watched to see that it is operating correctly without unusual noise or vibration. 2. STARTING UP: Start the fan and observe to see that it is rotating in the direction indicated by the direction arrow attached to the fan cylinder. Observe that the fan is operating smoothly without undue vibration. If it does vibrate excessively, stop the fan as soon as possible and check for out of balance due to misaligned blades, or loose bolts in the bearing housing. Start the circulating pump and let the circulating system settle down. Then with an ammeter check that fan when operating, is not causing the motor to draw more than nameplate amps. If more than nameplate amps is being drawn, re-pitch fan. Dump the water in the cold water basin via the drain twice within the first day of operation to ensure that the system is clean. Cold water collecting basin, normal operating water level in the basin at bottom of the cooling tower. Adjust the float valve arm to achieve this. In any case, enough depth must be maintained to prevent pump from pulling air into suction line. Water make-up and blow down. The amount of "make-up" water that is required to maintain adequate water depth in the cold water collecting basin depends upon the "evaporation loss", "drift loss" and ‘blow down". Water for the make-up averages between 0.1% to 1% of the cooling tower circulated water depending on cooling range and above mentioned governing factors. Make sure that the make-up float is operating properly and doesn’t leak when closed. See that cold water outlet suction screen is properly installed and that cavitation is not occurring (swirls of water in the vicinity of the outlet indicates the possibility of cavitation). 3. OPERATING: Refer to enclosed " Suggested Maintenance and Inspection Procedure" for a guide to preventative operating maintenance. Set up a regular schedule for maintenance of the cooling tower and the cooling system. Keep the water distribution systems and the cold water basin free of dirt and foreign matter. Regularly Check: -The circulating pump for speed, pressure or cavitation. -The pipelines for air, partially or inadvertently closed valves, dirt or restrictions. -The condenser being served by the cooling tower for scale, air or restrictions. -If a condenser becomes scaled badly; circulating water is usually retarded and pumping head is increased. Fill media must be kept level and clean. It is easier to prevent the deposition of foreign material than remove it at a later date. Motor lubrication, the lubrication and maintenance of each electric motor should be in accordance with the manufacturer's instructions. Fan - visually inspect fan operation daily and clean blades when necessary. 4. SHUT DOWN: Proper maintenance of equipment during shut down time will assure trouble free start up. As the intended period of the shut down increases in length, so will the extent of the protection required. Drain the water from the system, if necessary but leave the cold water basin full of water at all times. Electric motor if the cooling tower is to be out of service for a considerable period the motor should be removed from the cooling tower. Under normal circumstances however the motor will remain in the cooling tower, and be shut down. -Blow down the windings with low pressure air to remove rubbish and dirt, lubricate the bearings in accordance with manufacturers instructions. -Regularly (approximately every three to four weeks) turn fan shaft, several revolutions to re-coat the bearings with lubricant. -As the motor performance affects the successful operation of the cooling tower greatly, serious consideration should be given to have the motor serviced each annual shut down. Leaks throught the cooling tower casings should be sealed by tightening of securing fasteners and similar attention should be paid to structural fixings. Do maintenance or repair work whenever possible, while the cooling tower is completely shut down. WATER TREATMENT: Lakeside Cooling Towers do not act in the capacity of water treatment consultants and suggest that if required, qualified water treatment experts be consulted. Their competent advice will be invaluable in setting up a treating method of control, which will be both effective and economical. Your Lakeside cooling tower is constructed in the best practice, however the remainder of the cooling system must also be considered. SUGGESTED MAINTENANCE & INSPECTION PROCEDURE: DAILY: Electric Motor: - Check for vibration or unusual noises. Fan: - Check for vibration or unusual noises. Operating level of water: - Cold water basin. Cold water outlet screen: - Inspect for general condition and clean as necessary. Make-up float valve: - Inspect for correct operation. REGULARLY: Electric Motor: - Lubricate as per the Manufactures requirements. Cold water outlet: - Inspect for general condition. Hot water pipe: - Inspect and clean as necessary. Fill media & Eliminators: - Inspect and clean as per AS Codes. Water: - If water treatment is being used follow the recommended program Cold water basin: - Inspect and clean as AS Codes. ANNUALLY: Fan: - Repaint if necessary. Electric Motor: - Repaint if necessary and maintain in accordance with manufacturer instructions. Replace and/ or maintain those components, which require either of these to ensure that the cooling tower is in excellent working order. TROUBLE SHOOTING: COLD WATER TOO WARM: Cause: 1. Over-pumping. 2. Cooling tower fill media (a) fouled. (b) Damaged. 3. Not enough air. Remedy: 1. Reduce water flow to cooling tower to design conditions. 2. (A) Hose out with high-pressure water. (b) Repack cooling tower. 3. (A) Check motor current and voltage to be sure of correct contact kW. (b) Clean debris from cooling tower fill media and eliminators. (c) Adjust fan pitch to maximum current. UNUSUAL MOTOR NOISE: Cause: 1. Motor running on single phase. 2. Electrical unbalance. 3. Faulty or worn bearings. Remedy: 1. Stop motor and attempt to start it, motor will not start if single phased. Check wiring controls and motor. 2. Check voltage and currents of all three phases, correct if necessary. 3. Check lubrication, replace faulty or worn bearings. MOTOR RUNS HOT: Cause: 1. Motor overload, wrong voltage or unbalanced voltage. 2. Bearings over greased. 3. Poor ventilation. 4. Wrong grease. 5. Winding fault. Remedy: 1. Check voltage and current of all three lines against nameplates values. 2. Run motor up to speed to purge excessive grease. Contact manufacturer. 3. Clean motor. 4. Change to correct grease, see manufacturers lubrication instructions. 5. Check with ammeter, contact manufacturer. FAN NOISE: Cause: 1. Loose bolts. 2. Fan striking fan cylinder. Remedy: 1. Tighten bolts. 2. Adjust fan to correct position. UNUSUAL FAN VIBRATION: Cause: 1. Loose bolts. 2. Unbalanced fan. 3. Unbalanced motor. 4. Worn bearing or housing. 5. Bent shaft. Remedy: 1. Tighten all bolts on all mechanical equipment. 2. Be sure blades are properly positioned, all blades must be at same pitch. 3. Disconnect load operate motor, if motor still vibrates contact manufacturer. 4. Check bearings and mounting bolts. 5. Make sure fan and motor shafts are straight and properly aligned. SCALE OR FOREIGN MATERAIL IN WATER SYSTEM: Cause: 1. Lack of or insufficient blow down. 2. Water treatment. Remedy: 1, 2. Contact competent water treatment specialist.

Lakeside Cooling Towers (Australasia) Pty Ltd 3/198 Whitehorse Rd Blackburn VIC 3130 Australia Telephone:+61 03 9877 5066 Facsimile:+61 03 9877 5177 Email: info@lakesidect.com.au