Honeywell T775U2006 Installation Instructions Manual page 6

T775U SERIES 2000 CONTROLLER
C
S
SENSOR A
V
1
T
SENSOR B
T
THE T775U WILL ONLY ACCEPT 0-10 VDC AND 4-20 MA SENSORS.
1
IF REPLACING AN H775 CONTROLLER THAT USES A C7600B OR OTHER
2-10 VDC SENSOR, THE SENSOR MUST BE REPLACED. REPLACE THE
C7600B2008 SENSOR (2-10VDC OUTPUT) WITH THE H7655A1001
(0-10 VDC OUTPUT) SENSOR. THE H7655A1001 SENSOR USES THE SAME
ENCLOSURE STYLING AND WIRING AS THE C7600B.
Fig. 5. Sensor Wiring — 3-wire shielded cable
connection from Sensor A to 0-10 Vdc sensor
(H76xx humidity sensor shown).
C
S
SENSOR A
V
T
SENSOR B
T
3. THE T775 HAS AN INTEGRAL LOAD OF 500 OHMS, WHICH RESULTS IN A
10V DROP AT 20MA. TO USE LOOP POWERED WIRING, THE SENSOR MUST
BE CAPABLE OF OPERATION WITH 8V OR LESS ACROSS ITS TERMINAL.
Fig. 6. Sensor Wiring — 2-wire shielded cable
connection from 4-20 mA sensor to
T775 controller (loop powered wiring).
62-0255–05
SHIELDED CABLE
NOTES:
1. SHIELDED CABLE MUST BE
CONNECTED TO A SEPARATE
EARTH GROUND. HOWEVER,
DO NOT GROUND SHIELDED
CABLE AT SENSOR END.
2. TO MINIMIZE NOISE PICKUP,
MAKE SENSOR CONNECTION
FROM SHIELDED CABLE AS
CLOSE AS POSSIBLE TO
SENSOR BODY.
S C V
EXAMPLE OF
H76XX HUMIDITY
SENSOR;
0-10 VDC
CONNECTION
M24550
SHIELDED CABLE
NOTES:
1. SHIELDED CABLE MUST BE
CONNECTED TO A SEPARATE
EARTH GROUND. HOWEVER,
DO NOT GROUND SHIELDED
CABLE AT SENSOR END.
2. TO MINIMIZE NOISE PICKUP,
MAKE SENSOR CONNECTION
FROM SHIELDED CABLE AS
CLOSE AS POSSIBLE TO
SENSOR BODY.
S
V
M24890A
C
S
SENSOR A
V
T
SENSOR B
T
Fig. 7. Sensor Wiring — 2-wire shielded cable
connection from Sensor A to a 0-10 Vdc sensor
using separate transformer.
EXAMPLE OF P7640A 4-20 MA SENSOR CONNECTION
PWR OUT COM
SHIELDED CABLE
C
S
SENSOR A
V
T
SENSOR B
T
Fig. 8. Sensor Wiring — 2-wire 4-20mA sensor input
to T775 controller using a separate (Vdc only)
transformer.
6
SHIELDED CABLE
NOTES:
1. SHIELDED CABLE MUST BE
CONNECTED TO A SEPARATE
EARTH GROUND. HOWEVER,
DO NOT GROUND SHIELDED
CABLE AT SENSOR END.
2. TO MINIMIZE NOISE PICKUP,
MAKE SENSOR CONNECTION
FROM SHIELDED CABLE AS
CLOSE AS POSSIBLE TO
SENSOR BODY.
S
EXAMPLE OF
P7640A
PRESSURE
SENSOR;
0-10 VDC
CONNECTION
L1
(HOT)
24 VAC
L2
ZERO
12-30 VDC
POWER SUPPLY
S
+
–
C
NOTES:
1. SHIELDED CABLE MUST BE
CONNECTED TO A SEPARATE
EARTH GROUND. HOWEVER,
DO NOT GROUND SHIELDED
CABLE AT SENSOR END.
2. TO MINIMIZE NOISE PICKUP,
MAKE SENSOR CONNECTION
FROM SHIELDED CABLE AS
CLOSE AS POSSIBLE TO
SENSOR BODY.
WIRING
C
M24551
M24889A