401-405 SERIES
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There are two possible connection methods to the analog terminal
strip. The standard method is by inserting a cable through the
supplied cable gland with an external jacket that meets the
specifications of the following caution note and tightening down the
cable gland nut securely to seal against the cable jacket.
There is also an optional sealed circular connector that may be ordered
with the instrument. If this connector is ordered the internal terminal
board will be connected to pins on the circular connector. This option
will be supplied with the mating connector (if a power cable was not
ordered with the instrument). This mating connector has pins that must
be soldered to wires (24 - 28 AWG) in a customer supplied cable that
meets the specifications in the caution note below. Other sealing collets for cable diameters other than
specified below can be ordered from Bulgin PX0482 (3 – 5 mm) or PX0483 (5 – 7 mm). Ensure that
the parts are installed on the cable assembly correctly before assembling. Installation and removal of the
outer housing may damage the latches and prevent the connector from making a leak-free seal.
CAUTION
In order to maintain the environmental integrity of the enclosure
the power/signal cable jacket must have a diameter of 0.12 -
0.35” (3 – 9 mm) for the cable gland or 0.25 - 0.275” (6.5 – 7
mm) for the circular connector. The nut on the cable gland must
be tightened down sufficiently to secure the cable. This cable
must be rated for at least 85°C.
2.5.1. Power Supply
Ensure that the power source meets the requirements detailed in the specifications section. Hastings
offers several power supply and readout products that meet these standards and are CE marked. If
multiple flow meters or other devices are sharing the same power supply, it must have sufficient
capability to provide the combined maximum current.
Power is delivered to the instrument through pins 1 and 2 of the analog terminal strip located within the
electronics enclosure (see Figure 2-1). As shown in the pin-out diagram Figure 2-2, the positive polarity
of the power supply is connected to pin 2 and the negative is connected to pin 1. (For a unipolar power
supply, pin 1 is power common and pin 2 is +24V. For a bipolar ±15V power supply, pin 1 is -15V and
pin 2 is + 15V.) To allow for inadvertent reversal of the power polarity, an internal diode bridge will
ensure that the proper polarity is applied to the internal circuitry. A green LED located next to the
terminal strip will illuminate when the meter is properly powered. The power supply inputs are
galvanically isolated from all other analog and digital circuitry.
2.5.2. Analog Output
The indicated flow output signal is found on pins 3 and 4 of the terminal strip as shown in Figure 2-2.
The negative output pin 3 is galvanically isolated from chasis ground and from the power supply input
common. The 400 Series meters can be configured to provide one of many available current and voltage
outputs; the standard 4 -20 mA or the optional 0 -20 mA, 0-5 Vdc, 1-5 Vdc, or 0-10 Vdc.
NOTE
When the meter is configured with milliamp output it
cannot generate a signal that is below the zero current
value; therefore the 0-20 mA unit is limited in its ability
to indicate a negative flow with the analog signal.
2.1.1.1. Current Loop Output
The standard instrument output is a 4 - 20 mA signal proportional to the measured flow (i.e. 4 mA =
zero flow and 20 mA = 100% FS). An optional current output of 0 – 20 mA (where 0 mA = zero flow
and 20 mA = 100% FS) may be selected at the time of ordering.
If either current loop output has been selected, the flow meter acts as a passive transmitter. It neither
sources nor sinks the current signal. The polarity of the loop must be such that pin 4 is at a higher
potential than pin 3 on the flow meter terminal strip. Loop power must be supplied with a potential in
