NTI INSTALLATION MANUALS

Part 7 - Connecting Electrical Service

Connector

Description

HT Selv

No. of Location

Pin

1

+24V

ROOM THERMOSTAT

SELV (24V)

2

ROOM THERMOSTAT 1 SIGNAL

3

+5V

NTC SYSTEM

4

CASCADE NTC SENSOR SIGNAL

5

+5V

NTC TANK

SELV (5V)

6

BOILER NTC SENSOR SIGNAL

CN24

7

+5V

OUTDOOR SENSOR

8

OUTDOOR NTC SENSOR SIGNAL

9

+24V

ROOM THERMOSTAT 2

SELV (24V)

10

ROOM THERMOSTAT 2 SIGNAL

11

EBUS2 SIGNAL

EBUS2

SELV (24V)

12

GROUND

1

GROUND

2

PWM FAN-DRIVER

FAN MANAGEMENT

SELV (24V)

CN16

3

HALL_EFFECT SENSOR

4

+24V

1

+24V

2

GROUND

EXTERNAL CLIP-IN

SELV (24V - 5V)

CN19

3

CLIP-IN SERIAL TX SIGNAL

4

CLIP-IN SERIAL RX SIGNAL

1

+5V

2

GROUND

HMI

3

HMI SERIAL TX SIGNAL

SELV (24V - 5V)

CN12

4

HMI SERIAL RX SIGNAL

5

+24V

1

PWM PUMP SIGNAL

PWM PUMP

2

NOT USED

SELV (24V)

CN22

3

GROUND

FLAME

1

FLAME SENSOR SIGNAL

HT (110Vrms) AC

CN23

1

+5V

2

GROUND

3

MODE

SERVICE TOOL SERIAL INTERFACE

SELV (24V - 5V)

CN18

4

SERIAL TX SIGNAL TO PC

5

SERIAL RX SIGNAL FROM PC

6

+24V

Table 21 - Boiler Wiring - 2

54