73
RTAA-IOM-3
2. Isolated 2-10 VDC Voltage Source
Input
Set DIP Switch SW1-1 of Options
Module 1U2 to “OFF”. Connect the
voltage source to terminals TB1 -4 (+)
and TB1 -5 (-) on Options Module
1U2. CWS is now based on the
following equation:
CW Setpoint 0 F = (VDC x 8.125) -
16.25
Sample values for CWS vs. VDC
signals are shown in Table 13.
Minimum setpoint
= 0 F (2.0 VDC input)
Maximum setpoint
= 65 F (9.4 VDC input)
Maximum continuous input voltage
= 15 VDC
Input impedance = 40.1 Kohms
SW1 -1 off)
3. Isolated 4-20 mA Current Source
Input
Set DIP Switch SW1-1 of Options
Module 1U2 to “ON”. Connect the
current source to terminals TB1-4
(+)and TB1-5 (-). CWS is now based
on the following equation:
Setpoint °F = (mA x 4.0625) - 16.25
Sample values for CWS vs. mA
signals are shown in Table 13.
Minimum setpoint = 0 F (4.0 mA)
Maximum setpoint = 65 F (18.8 mA)
Maximum continuous = 30 mA
input current
Input impedance = 499 ohms
SW1 -1 on)
Note: The negative terminal TB1 -5 is
referenced to the UCM chassis ground.
To assure correct operation, 2-10 VDC
or 4-20 mA signals must be isolated or
“floating” with respect to the UCM
chassis ground. See Figures 34 thru 36.
External Current Limit Setpoint
(CLS): Remote Resistor/
Potentiometer, Voltage Source 2-10
VDC or Current Source 4-20 mA
This option allows the external setting
of the Current Limit Setpoint,
independent of the Front Panel Current
Limit Setpoint, by one of three means:
1. A remote resistor/potentiometer
input (fixed or adjustable)
2. An isolated voltage input 2-10 VDC
3. An isolated current loop input 4-20
mA
Methods 2 and 3 are usually used in
interfacing with a Generic BAS.
To enable external Current Limit
Setpoint operation, Item 31 of Menu 3,
“External Current Limit Setpoint WE”,
should be set to “E” using the Front
Panel Operator Interface.
1. Remote Resistor/Potentiometer Input
To cover the entire range of Current
Limit Setpoints; (40 to 120%), a field
furnished 50 Kohm log taper
potentiometer (±10%) and a fixed
820 ohm (±1 0%) 1/4 Waft resistor
should be wired in series and
connected to terminals TB1 -6 and
TB1 -8, of options module 1U2, as
shown in Figure 39.
Table 14
Input Values Vs. External Current Limit Setpoint
Inputs
Resulting Current
Resistance (Ohms)
Current (mA)
Voltage (Vdc)
Limit Setpoint (% RLA)
49000
4.0
2.0
40
29000
6.0
3.0
50
19000
8.0
4.0
60
13000
10.0
5.0
70
9000
12.0
6.0
80
6143
14.0
7.0
90
4010
16.0
8.0
100
2333
18.0
9.0
110
1000
20.0
10.0
120
Figure 39
Resistor and Potentiometer
Arrangement for External
Current Limit Setpoint
Содержание RTAA-130
Страница 2: ... American Standard Inc 1991 ...
Страница 8: ...8 RTAA IOM 3 ...
Страница 13: ...13 RTAA IOM 3 Figure 3 Typical RTAA Packaged Unit 240 400 Tons Control Panel Evaporator Outlet Inlet ...
Страница 24: ...24 RTAA IOM 3 ...
Страница 26: ...26 RTAA IOM 3 Figure 9 Dimensions and Clearances for RTAA Packaged Unit 130 to 200 Ton RTAA SU 1000E ...
Страница 27: ...27 RTAA IOM 3 Figure 10 Dimensions and Clearances for RTAA Packaged Unit 240 300 Ton RTAA SU 1001C ...
Страница 28: ...28 RTAA IOM 3 Figure 11 Dimensions and Clearances for RTAA Packaged Unit 340 to 400 Ton RTAA SU 1002C ...
Страница 38: ...38 RTAA IOM 3 RTAA SA 2002C Figure 19 Spring Isolator Placement for Typical RTAA Packaged Unit 240 400 Tons ...
Страница 46: ...46 RTAA IOM 3 Figure 24 Typical Domestic Water Heater Piping Figure 25 Typical Domestic Water Heater Piping ...
Страница 50: ...50 RTAA IOM 3 Figure 30 Refrigerant Circuit Identification ...
Страница 52: ...52 RTAA IOM 3 Figure 31 Remote Evaporator Piping Example ...
Страница 58: ...58 RTAA IOM 3 Continued on Next Page Figure 34 Typical Field Wiring for RTAA Packaged Unit 130 to 200 Tons ...
Страница 59: ...59 RTAA IOM 3 Continued from Previous Page See Notes on Next Page ...
Страница 61: ...61 RTAA IOM 3 Figure 35 Typical Field Wiring for RTAA Packaged Unit 240 400 Tons Continued on Next Page ...
Страница 63: ...63 RTAA IOM 3 Continued from Previous Page See Notes on Page 61 ...
Страница 64: ...64 RTAA IOM 3 Figure 36 Typical Field Wiring for RTAA With Remote Evaporator Option Continued on Next Page ...
Страница 65: ...65 RTAA IOM 3 Continued from Previous Page See Notes on Page 61 ...
Страница 76: ...76 RTAA IOM 3 ...
Страница 78: ...78 RTAA IOM 3 Figure 40 Refrigeration System and Control Components Single Circuit Continued on Next Page ...
Страница 80: ...80 RTAA IOM 3 Figure 41 Refrigeration System and Control Components Duplex Circuit Continued on Next Page ...
Страница 92: ...92 RTAA IOM 3 Figure 51 Operator Interface Controls ...
Страница 120: ...120 RTAA IOM 3 ...
Страница 126: ...126 RTAA IOM 3 Figure 56 Unit Sequence of Operation RTAA 240 to 400 Tons Continued on Next Page ...
Страница 127: ...127 RTAA IOM 3 Continued from Previous Page 2307 1566C ...
Страница 128: ...128 RTAA IOM 3 Figure 57 Unit Sequence of Operation RTAA 130 to 200 Tons 2306 9122A ...
Страница 132: ...132 RTAA IOM 3 Figure 58 Operator s Log ...
Страница 138: ...138 RTAA IOM 3 ...