A.O. Smith BTN 120 THRU 400/A Series - Manual (Page 20)

20
HEATER WIRING
All electrical work must be installed in accordance with the latest
version of the National Electrical Code ANSI/NFPA No. 70, must
conform to all local code authority having jurisdiction.
AN
ELECTRICAL GROUND IS REQUIRED TO REDUCE RISK OF
ELECTRICAL SHOCK OR POSSIBLE ELECTROCUTION.
If any of the original wire as supplied with the appliance must be
replaced, use only type 105
0 C thermoplastic or equivalent. 250 0 C
type F must be used for the flame sensor leads and the spark
ignition cable must be high voltage 250
0 C.
FIGURE 9 - SINGLE UNIT WIRING DIAGRAM BTN-120 THROUGH 400A