Thermostat Settings - Electronic Controls - A.O. Smith 52 Instruction Manual

Figure 10. Thermodisc
Thermostat
Table 6 shows the approximate time-to-burn relationship for
normal adult skin.
Table 7. Time to Burn at Various Temperatures
Water Time for 1st Degree Burn
Temperature °F (Less Severe
110 (normal shower temp.)
116 (pain threshold)
116 35 minutes
122 1 minute
131 5 seconds
140 2 seconds
149 1 second
154 instantaneous
(U.S. Government Memorandum, C.P.S.C., Peter L. Armstrong, Sept. 15,1978)

THERMOSTAT SETTINGS - ELECTRONIC CONTROLS

These models are equipped with an electronic control system.
The control system senses temperature from a factory installed
Immersion Temperature Probe (see
Set Point" is adjusted to control water temperature. This is an
adjustable user setting in the control system's "Temperatures
Menu." This and all control system menus are accessed
through the UIM (User Interface Module - see Figure 12.
UIM (User Interface Module)) located on the front panel of
the water heater.
Water temperature over 125°F (52°C)
can cause severe burns instantly
resulting in severe injury or death.
Children, the elderly and the
physically or mentally disabled are at
highest risk for scald injury.
Feel water before bathing or
showering.
Temperature limiting devices such as
mixing valves must be installed
when required by codes and to
ensure safe temperatures at fixtures.
The Operating Set Point is adjustable from 90°F/42°C to
190°F/88°C. The factory setting is 120°F/49°C. See the
Electronic Control Models Operation section of this manual
for instructions on how to adjust the Operating Set Point and
other user settings.
40A 120-277 VAC
25A.480 VAC
125VA.PT.DTY.
120-480 VAC
LO
HI
MED
APCOM
INC
30A 120-250 VAC
22A 277 VAC
12.5A 480VAC
125 VA.PT.DTY. 120-480 VAC
Figure 11. Apcom
Thermostat
Time for Permanent
Burns 2nd & 3rd Degree
Burns)
(Most Severe Burns)
45 minutes
5 minutes
25 seconds
5 seconds
2 seconds
1 second
). The "Operating
Figure 2
Figure 12. UIM (User Interface Module)
Set the Operating Set Point at the lowest setting which
produces an acceptable hot water supply. This will always give
the most energy efficient operation.
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