Takagi T-K3 Service Manual

T-K3 Service Manual
Ver. 1.05
51
CONFI DENTIAL
12-8. T-K3 ON/OFF conditions: BTU requirements for Cont inuous mode
A. Calculating the T-K3’s ON/OFF conditions
【Condition needed to turn the T-K3 ON】
( T
set
– T
in
) × GPM × 500 > 11,900
【Condition needed to turn the T-K3 OFF】
( T
set
– T
in
) × GPM × 500 < 7,440 or T
in
= T
set
Where: T
set
= Output set temperature and T
in
= Inlet temperature
B. Calculation example
Set temperature: T
set
= 122 ˚ F Flow rate = 2.5 GPM
【Condition needed to turn the T-K3 ON】
(122 – T
in
) × 2.5 × 500 > 11,900 T
in
< 112.5˚ F
【Condition needed to turn the T-K3 OFF】
(122 - T
in
) × 2.5 × 500 < 7,440 T
in
> 116.0 ˚ F
The outlet temperature at that moment w ill be 120 ˚F
C. ON/OFF table
Flow rate (GPM) set temperature
(˚F)
1.0 1.5 2.0 2.5 3.0 3.5 4.0
ON 89.2 97.1 101.1 103.5 105.1 106.2 107.1
113
OFF 98.1 103.1 105.6 107.0 108.0 108.7 109.3
ON 98.2 106.1 110.1 112.5 114.1 115.2 116.1
122
OFF 107.1 112.1 114.6 116.0 117.0 117.7 118.3
ON 107.2 115.1 119.1 121.5 123.1 124.2 125.1
131
OFF 116.1 121.1 123.6 125.0 126.0 126.7 127.3
ON 116.2 124.1 128.1 130.5 132.1 133.2 134.1
140
OFF 125.1 130.1 132.6 134.0 135.0 135.7 136.3
ON 134.2 142.1 146.1 148.5 150.1 151.2 152.1
158
OFF 143.1 148.1 150.6 152.0 153.0 153.7 154.3
ON 143.2 151.1 155.1 157.5 159.1 160.2 161.1
167
OFF 152.1 157.1 159.6 161.0 162.0 162.7 163.3
ON 161.2 169.1 173.1 175.5 177.1 178.2 179.1
185
OFF 170.1 175.1 177.6 179.0 180.0 180.7 181.3

Takagi T-K3 Specifications

General

Type	Tankless
Installation Type	Indoor
Maximum BTU Input	199, 000 BTU/h
Gas Connection Size	3/4"
Vent Size	3"
Hot Water Flow Rate (at 35°C rise)	6.6 GPM
Maximum Input	199, 000 BTU/h