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manual abstract
Next, turn on all other fuel burning appliances within the same room so they will operate at their full input. Repeat step C above, checking the draft on each appliance. FIGURE 9 SAFETY RELIEF VALVES Your local code authority may have other specific relief valve requirements not covered below. WARNING THE PURPOSE OF A SAFETY RELIEF VALVE IS TO AVOID EXCESSIVE PRESSURE OR TEMPERATURE INTO THE STEAM RANGE WHICH MAY CAUSE SCALDING AT FIXTURES, TANK EXPLOSION, SYSTEM OR BOILER DAMAGE. TO AVOID SCALDING OR WATER DAMAGE A DRAIN LINE MUST BE CONNECTED TO A RELIEF VALVE TO DIRECT DISCHARGE TO A SAFE LOCATION. A DRAIN LINE MUST NOT BE REDUCED FROM THE SIZE OF THE VALVE OUTLET AND IT MUST NOT CONTAIN ANY VALVES BETWEEN THE BOILER AND THE RELIEF VALVE OR THE RELIEF VALVE AND THE DRAIN EXIT. IN ADDITION, THERE SHOULD NOT BE ANY RESTRICTIONS IN A DRAIN LINE NOR SHOULD IT BE ROUTED THROUGH AREAS WHERE FREEZING CONDITIONS MIGHT OCCUR. DO NOT THREAD OR CAPTHE DRAIN LINE EXIT. RESTRICTING OR BLOCKINGA DRAIN LINE WILL DEFEAT THE PURPOSE OF THE RELIEF VALVE AND MAY CREATE AN UNSAFE CONDITION. INSTALL A DRAIN LINE WITH A DOWNWARD SLOPE SUCH THAT IT NATURALLY DRAINS ITSELF. If any safety relief valve is replaced, the replacement valve must comply with the latest version of the ASME Boiler and Pressure Vessel Code, Section IV or CSA B51, as applicable. Select a relief valve with a discharge NOT less than the boiler input, and a pressure rating NOT exceeding the working pressure of any component in the system. A. O. Smith supplies Canadian HW boilers for hot water supply systems with a 125 psi pressure relief valve. This valve must be installed in the water outlet as near to the boiler as possible. A. O. Smith United States HW and Canadian HWB boilers for space heating are shipped with a 50 psi pressure relief valve. This valve must be installed in the water outlet as near to the boiler as possible. An ASME rated temperature and pressure relief valve must be installed on each and every water storage tank in a hot water supply system. 15 1515151515 The storage tank temperature and pressure (T & P) relief valve must comply with the applicable construction provisions of the Standard for Relief Valves and Automatic Gas Shutoff Devices for Hot Water Supply Systems, Z21.22 and/or CAN1-4.4. The T & P valve must be of the automatic reset type and not embody a single-use type fusible plug, cartridge or linkage. The T & P relief valve should have a maximum temperature rating of 1000C (2100F), a pressure rating NOT exceeding the lowest rated working pressure of any system component, and a discharge capacity exceeding the total input of the water boilers supplying water to the storage tank. Locate the T & P relief valve (a) in the top of the storage tank, or (b) in the side of the tank on centerline within the upper 6 inches from the top of the tank. See figures 20 to 31. Tapping shall be threaded in accordance with the latest version of the Standard for Pipe Threads, General Purpose (inch), ANSI/ASME B1.20.1 Mark location with a Class lll label. See ANSI Z21.10.1, Part 1, MARKING, See CAN/CSA B149.1-00. WIRING CONNECTIONS CAUTION LABEL ALL WIRES PRIOR TO DISCONNECTION WHEN SERVICING CONTROLS. WIRING ERRORS CAN CAUSE IMPROPERAND DANGEROUS OPERATION. VERIFY PROPER OPERATION AFTER SERVICING. 1. CONVENTIONAL INSTALLATIONS ALL ELECTRICAL WORK MUST BE INSTALLED IN ACCORDANCE WITH NATIONAL ELECTRICAL CODE, ANSI/NFPA70 AND/OR THE CANADIAN ELECTRICAL CODE, PART 1, CSA C22.1, ELECTRICAL CODE AND MUST CONFORM TO LOCAL REGULATIONS. The boiler, when installed, must be electrically bonded to ground in accordance with the requirements of the authority having jurisdiction or, in the absence of such requirements, with the National Electrical Code, ANSI/NFPA 70 and/or the Canadian Electrical Code Part 1, CSA C22.1, Electrical Code. STRICT ADHERENCE TO PIPING AND WIRING DIAGRAMS IS REQUIRED TO PREVENT CONSTANT PUMP OPERATION WHEN SYSTEM TEMPERATURE CONTROL IS SATISFIED. OTHERWISE THE WARRANTY IS VOID AS STIPULATED IN THE LIMITED WARRANTY ON THE INSTRUCTIONS MANUAL. The electrical connections must be made so that the circulator will operate before the gas valve opens. At no time may the controlling system allow the burner to fire when there is no water flow through the boilers. Refer to the diagrams in fig’s. 10 thru 11C for proper wiring sequence with conventional single boiler installations. The THERMAL BALANCER shown is factory included by A. O. Smith as part no. 98190. This device serves as a pump shutdown delay switch to balance the rising boiler water temperature to system temperature before the pump stops. Overshooting of boiler temperature is prevented and stack loss after shutdown is negligible. WARNING AN ELECTRICAL GROUND IS REQUIRED TO REDUCE RISK OF ELECTRIC SHOCK OR POSSIBLE ELECTROCUTION. Make the ground connection to the screw provided in the electrical supply junction box on the boiler. IF ANY OF THE ORIGINAL WIRE, AS SUPPLIED WITH THE APPLIAN...
Other models in this manual:Water Heaters - HW-399 (1.23 mb)
Water Heaters - HW-520 (1.23 mb)
Water Heaters - HW-670 (1.23 mb)
Water Heaters - HWB-300 (1.23 mb)