16
16
16
16
16
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 100
0
C (210
0
F), 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
IMPROPER AND DANGEROUS OPERATION.
VERIFY PROPER OPERATION AFTER SERVICING.
1.
CONVENTIONAL INSTALLATIONS
ALL ELECTRICAL WORK MUST BE INSTALLED IN ACCORDANCE
WITH NATIONAL ELECTRICAL CODE, ANSI/NFPA 70 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
APPLIANCE, MUST BE REPLACED, IT MUST BE REPLACED WITH
TYPE 105
0
C WIRE OR ITS EQUIVALENT, EXCEPT FOR THE FLAME
SENSOR AND IGNITION CABLE WHICH ARE 250
0
C AND WIRES
CONNECTED TO THE COIL PROTECTOR WHICH ARE 200
0
C.
