Blower Speed Control Bth 199 And 250 - A.O. Smith Cyclone Xi Service Handbook

BLOWER SPEED CONTROL BTH 199 AND 250

The input of the BTH 199 and BTH 250 is
determined by blower. The input of the water
heater may be determined by clocking the
meter as shown on page 5 or by making sure
the blower is receiving the proper signal.
The blower rpm is controlled by the Central
Control Board (CCB). The rpm of the blower
may be measured by attaching a
MULTIMETER that has a Hertz (Hz) setting
as shown in the illustration to the right. If the
Hz signal is within +/- 5% of the numbers in
the chart below the reading is normal.
High
Model
Speed Hz
199 N 133
250 N 133
199 LP 200
250 LP 266
Note: Removing the plug shown in the
illustration will cause the blower to accelerate
and the input of the water heater to increase
to a much higher rate. This may cause
damage to the water heater.
A.O. Smith – Technical Training Department
CYCLONE Xi COMMERCIAL GAS WATER HEATER
BTH 120 thru 500 SERVICE HANDBOOK
Low
Speed Hz
87
87
156
96
Servicing should only be performed by a Qualified Service Agent
Meter black lead is connected to ground (not
shown) and the red lead is connected to an
open terminal on blower speed control
connection.
37
Meter red probe
connected to
open terminal on
plug
Ashland City, Tennessee © 2009
316586-000