A.O. Smith T-H2-DV User Manual

T-H2-DV/T-H2-OS Service Manual
Ver. 1.01
72
CONFIDENTIAL
12-8. (B). Pump control ON/OFF conditions: BTU requirements
A. Calculating the ON/OFF conditions of the T-H2-DV or T-H2-OS
【Condition needed to turn the pump ON】
 ( T
set
– T
in
) × GPM × 500 > 14,880
【Condition needed to turn the pump OFF】
5 minutes after activation, if the computer detects a BTU requirement of less than 18,600 BTU/h, the
computer will stop the pump 90 seconds.
( T
set
– T
in
) × GPM × 500 < 14,880 or T
in
= T
set
Where: T
set
= Set temperature and T
in
= Inlet temperature
B. Calculation example
Set temperature: T
set
= 120 ˚F    Flow rate = 2.5 GPM
【Condition needed to turn the pump ON】
( 120 – T
in
) × 2.5 × 500 > 14,880 T
in
< 108.1˚F
【Condition needed to turn the pump OFF】
( 120 – T
in
) × 2.5 × 500 < 14,880 T
in
> 108.1˚F
C. ON/OFF table (ON values are the same as OFF values)
Set temperature
(˚F)
Flow rate (GPM)
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
100 40.5 70.2 80.2 85.1 88.1 90.1 91.5 92.6
115 55.5 85.2 95.2 100.1 103.1 105.1 106.5 107.6
120 60.5 90.2 100.2 105.1 108.1 110.1 111.5 112.6
135 75.5 105.2 115.2 120.1 123.1 125.1 126.5 127.6
145 85.5 115.2 125.2 130.1 133.1 135.1 136.5 137.6
155 95.5 125.2 135.2 140.1 143.1 145.1 146.5 147.6
165 105.5 135.2 145.2 150.1 153.1 155.1 156.5 157.6
185 125.5 155.2 165.2 170.1 173.1 175.1 176.5 177.6

A.O. Smith T-H2-DV Specifications

General

Brand	A.O. Smith
Model	T-H2-DV
Category	Water Heater
Language	English