44
Installation
•
Make sure that all electrical installations and connections are in accordance with
national and local electrical codes.
•
Before performing any connection, disconnect the sampler from the power source.
•
If the area is wet or hands or clothing or wet, do not attempt to make any connection
or handle the electrical components of the sampler when connected to the AC line
power.
•
If the circuit breaker or fuse in the AC power source is tripped, determine the cause
before restoring power to the sampler.
•
Make sure the power circuit is grounded and protected with a Ground Fault Interrupter
(GFI).
4.10 Auxiliary receptacle pin identification
Note: In some installations, it is necessary to connect external equipment to the Pulse input, Special
output and/or Program Complete output vial long cable runs. Since these are ground-referenced
pulse interfaces, there is a possibility of false signalling due to transient ground differences between
each end of the cable. High ground differentials are particularly likely in heavy industrial
environments. In such circumstances, it may be necessary to use third-party galvanic isolators (e.g.
optocouplers) in line with the affected signal(s). For the Current Input, external ground isolation is
not usually necessary because the 4–20mA transmitter normally provides isolation.
Pin A/White (12 V dc)
Powers an external device or flow meter. Must be used in conjunction with Pin B (ground).
Pin B/Blue (Ground)
1
1
All mains powered equipment that connects to the controller terminals should be NRTL listed.
Connected to dc ground and is isolated from the earth ground found in the ac power line.
Pin C/Yellow (Pulse Input)
With the sampler in Flow Proportional mode and connected to an external flow meter, a 5 to
12 V dc input pulse lasting at least 25 milliseconds will cause the sampler to decrement one
count. The 12 V dc line found on Pin A can be used directly with a simple contact closure to
Pin C or an external 5 to 12 V dc pulse may be applied providing the ground side of the
external signal is connected to the sampler ground at Pin B. This count is actuated at the
beginning of the input signal (the leading edge of the pulse).
Pin D/Black
(Liquid Level Actuator/
Auxiliary Control Input)
This line is held at 5 V dc inside the sampler. When shorted to ground (Pin B), a signal is sent
to the microprocessor inside the sampler causing it to “wake up” and begin or resume its
sampling program. It can be used in conjunction with a simple level float to actuate the
sampler when liquid is present or to take over after a second sampler has finished its
program. It may also be used with any device (such as a pH meter) that produces a dry
contact output to control the sampler in response to some user-defined condition (i.e. high or
low pH); must be used in conjunction with Pin B.
Pin E/Red (Special Output)
Normally at 0 V dc, this line goes to 12 V dc upon any of the selected events.
Pin F/Green
(Program Complete Output)
Normally an open circuit, this line switches to ground for 90 seconds at the conclusion of the
sampling program. Used to “wake up” another sampler to take over sampling or to signal an
operator or data logger upon the completion of the sampling program. This pin is also used to
signal the bottle full condition in a single bottle/continuous mode, and will transmit the bottle #
to a 950 Flow Meter if the program complete signal is disabled.
A
B
C
D
E
F
Goodnal STP ST041 Pre Treatment (Sigma 900 MAX All Weather Refrigerated Sampler) Vendor Manual
Q-Pulse Id VM373
Active 29/10/2013
Page 44 of 122
