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Helios PD2-6100 Strain Gauge, Load Cell, and mV Meter
Acknowledging Relays
There are three ways to acknowledge relays
programmed for manual reset:
1.
Via the programmable front panel function keys
F1-F3 (Example: F3 assigned to ACK).
Note: If F3 is assigned to ACK, then it cannot be
used for Tare.
MENU RIGHT
UP
F1
F2
MENU
ZERO
RESET
2.
Remotely via a normally open push button wired
to the F4 terminal.
3.
Remotely via a normally open push button wired
to one of the digital inputs and the +5 V terminal
on the digital I/O connections.
O1 O2 O3 O4 G
5 VDC
+5
I1 I2 I3 I4
When the ACK button or the assigned digital input is
closed, all relays programmed for manual reset are
acknowledged.
Acknowledging Relays with Remote
Control Station
Relays may be remotely acknowledged by connecting
the
PDA2361-A
to either the F4 terminal or a digital
input as described above.
Pump Alternation Control
Applications (Altern)
For pump control applications where two or more
similar pumps are used to control the level of a tank, it
is desirable to have all the pumps operate alternately.
This prevents excessive wear and overheating of one
pump over the lack of use of the other pumps.
Up to 4 relays can be set up to alternate every time
an on/off pump cycle is completed. The set points and
reset points can be programmed, so that the first
pump on is the first pump off.
ACK
F3
ACK
TARE
Ground
ACK
Application #1: Pump Alternation
Using Relays 1 & 2
1.
Relays 1 and 2 are set up for pump alternation.
2.
Relays 3 and 4 are set up for low and high alarm
indication.
Set and Reset Point Programming
Relay
Set Point
1
30.000
2
35.000
3
4.000
4
40.000
Pump Alternation Operation
1.
Pump #1 turns on when level reaches 30.000,
when level drops below 10.000 pump #1 turns
off.
2.
The next time level reaches 30.000, pump #2
turns on, when level drops below 10.000 pump
#2 turns off.
If the level doesn't reach 35.000 pump #1 and
3.
pump #2 will be operating alternately.
4.
If pump #1 cannot keep the level below 35.000
pump #2 will turn on at 35.000, then as the level
drops to 10.000 pump #1 turns off, pump #2 is
still running and shuts off below 5.000.
5.
Notice that with the set and reset points of pump
#2 outside the range of pump #1, the first pump
on is the first pump to go off. This is true for up to
4 alternating pumps, if setup accordingly.
6.
Relay #3 will go into alarm if the level drops
below 4.000 and relay #4 will go into alarm if the
level exceeds 40.000.
7.
Adding the 4 external relays expansion module
allows using the 4 SPDT internal relays for pump
alternation and the 4 SPST external relays for
high, high-high, low, and low-low alarm
indication.
Application #2: Pump Alternation
Using Relays 3 & 4
1.
Relays 1 and 2 are set up for low and high alarm
indication.
2.
Relays 3 and 4 are set up for pump alternation.
Set and Reset Point Programming
Relay
Set
Point
1
495
2
7500
3
7000
4
6000
The following graphics provide a visual representation
of a typical pump alternation application with high and
low alarm monitoring:
39
Instruction Manual
Reset Point
Function
10.000
Controls
pump #1
5.000
Controls
pump #2
9.000
Controls
low alarm
29.000
Controls
high alarm
Reset
Function
Point
750
Controls low alarm
6900
Controls high alarm
900
Controls backup
pump
1000
Controls main pump
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