Ashcroft ATE-2, Operation And Maintenance Manual

Page: 25 / 84

23
Main Menu
24v Loo p Su pp l y On/Off
Units…
Setu p …
Modes…
Calibrate…
–0.07
inH2O psi
0.005
Enable and Disable 24 Vdc Power Supply
(Non-intrinsically safe version only)
Press MENU key
Press DOWN or UP ARROW key to highlight “24v Loop Supply
On/Off”
Press ENTER
HHC will return to Measurement Mode and “24v” is shown on
center bottom of display to indicate power supply is activated.
To Disable 24V Power Supply
Press MENU key
Press DOWN or UP ARROW key to highlight “24v Loop Supply
On/Off”
Press ENTER
HHC will return to Measurement Mode, “24v” has been removed
from the display. Power supply is now deactivated.
Note: In power supply off condition leakage of approximately
1.0 V and 0.03 mA will be measurable, this voltage and current is
not adequate to drive most loads.
Loop Power Overload and Reset
The 24v loop supply is rated to source up to 35 mA of current.
Overload protection is activated at approximately 54 mA. If the
load current exceeds this value, the overload protection function
deactivates the loop supply and will switch off the “24V” icon on
the LCD display. In the event of an overload the following Error
message will be displayed:
+
–
+
–
24Vdc Out
0-33Vdc In
0-22mA In
COM
24Vdc Out
0-33Vdc In
0-22mA In COM
24Vdc Out
0-33Vdc In
0-22mA In
COM
RESISTOR*
EXTERNAL
24 VOLT DC
SWITCH HOOKUP
USING INTERNAL
SUPPLY SWITCH
NORMALLY OPEN
SWITCH HOOKUP
USING INTERNAL
SUPPLY SWITCH
NORMALLY OPEN
EXTERNAL
24 VDC SUPPLY
Note that you can use a normally closed switch as well
*Resistor should be sized to allow current as follows:
2 mA < I < 36 mA, 2 mA 12 k , 35 mA 686
SWITCH HOOKUP
USING INTERNAL
SUPPLY SWITCH
NORMALLY OPEN
SECTION 14 j. WIRING DIAGRAMS CONT.
SECTION 14 k. 24 VDC POWER SUPPLY ENABLE
AND DISABLE