The following diagrams show how to wire the (2) relay
outputs of the PC100. Each relay has a single set of form C
contacts (one normally open and one normally closed).
Relay outputs are typically used to energize or de-energize
solenoids in valves, motors, pumps, and alarms.
CAUTION: Because the relays may be switching high
power devices, DO NOT use the PC100 AC power supply to
power valves or pumps. This might generate electrical noise
and could damage the processor
.
TYPICAL APPLICATIONS
• SINGLE STAGE VALVE CONNECTION
Always use Relay K2 when connecting to a single stage
valve. At the preset batch point the relay will be de-ener-
gized, cutting power to the valve solenoid and causing the
valve to shut off.
• MAIN PUMP CONNECTION
Relay K2 is connected to the pump motor to energize at
the beginning of the batch and de-energize at the end. If
used with a one stage valve, use Relay K1 and program
prewarn to zero (0). (See page15.)
• TWO STAGE VALVE CONNECTION
Relay K1 is connected to the first stage valve solenoid to
partially close the valve and Relay K2 is connected to the
second stage for final valve shutdown.
OPTIONAL APPLICATIONS
• FEED PUMP CONNECTION
Relay K1 can be connected to a feed pump to inject or add
fluids to the main batch on a preset time basis. (Refer to F32)
• HI AND/OR LOW FLOW ALARM
Relay K1 can be connected to an alarm to provide a
permanent or temporary warning signal when a low or hi
flow preset point has been exceeded. To do this, move wire
from terminal #8 and connect to terminal #7. See how to
program the hi and low flow set points on page 14.
7
• OPEN COLLECTOR OUTPUT (Type C)
PFT2E, PFT3E, FT1E transmitters and meter mount
PC100 sensors generate output signals from a current
sinking NPN (open collector) transistor. The PC100 pro-
vides the necessary DC power from terminal #20 only when
on AC main power.
• FT420XP (TYPE D)
This transmitter has dual output, a 4-20 mA analog signal,
and an unscaled open collector transistor pulse.
• PFT3 (TYPE E)
This transmitter consists of a Reed switch sensor which
generates contact bounce. It is similar in operating to a Type
A-2 transmitter.
Therefore, installation of a jumper between terminals
#12 and #13 is required. This effectively filters the unwanted
extra closures caused by contact bounce. (Jumper termi-
nals #11 and #12 if using transmitter input 2 on terminal
#10).
HOW TO CONNECT VALVES,
MOTORS, PUMPS AND ALARMS
FT420XP
Summary of Contents for PC100
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