Brooks Instrument MT3809G - Manual (Page 37)

Installation and Operation Manual
X-VA-MT3809G-MT3810G-eng
Part Number: 541B182AAG
September, 2013
Models MT3809G & MT3810G
2-7
Section 2 Installation
4. The shielded cable must be used for hook up. The shield should be
connected to chassis ground at the transmitter end and should be taped up
and not connected at the receiver end. Insulation of the shield at the
receiving end is especially important for intrinsically safe installations.
5. The maximum resistance of the loop resistor, the associated cable and
the barrier is determined by the power supply voltage and is shown
graphically in Figure 1-9.
6. The pulse and alarm outputs function as isolated switch closures
(optically isolated open collector-emitter) and must be supplied with a
power source, as shown in wiring diagram, Figure 1-5. Observe polarity
and do not exceed 30 volts for the supply and limit load current to 20 mA
for each output.
7. The zero function is activated by momentarily shorting the zero terminals
on the wiring block. This may be accomplished with any conductive jumper
or a switch which can be remotely mounted. The hazardous area
classification will determine the wiring methods used for this switch.
8. After installation and powering of the loop, the transmitter must be
zeroed, both electrically and mechanically. This operation will compensate
for any stray magnetic effects in the vicinity of the transmitter. Flow must
be zero and when the zero function is momentarily activated. The pointer
must also be adjusted to the reference line on the scale using the
adjustment screw on the face of the pointer, next to the hub. The zero
function may be activated as part of a periodical maintenance check.
9. Under actual flow conditions, verify that the transmitter output matches
the mechanical pointer position and that the alarms and pulse outputs are
working properly. If a discrepancy is noted, the HART communications
channel can be used to verify or adjust the transmitter settings. The HART
hand held communicator provides a simple means to accomplish this
check anywhere in the loop.
2-7 Installation of the Model MT3809 Flowmeter with a Transmitter with Inductive Alarms (1 or 2 switches)
a. Install the meter as described in Section 2-5
b. Install the transmitter as described in Section 2-6
c. Install the inductive alarms as indicated below Section 2-8
2-8 Installation of the Model MT3809 Flowmeter with Inductive Alarms (1 or 2 switches)
Install the meter as described in Section 2-5
To install the inductive alarms (1 or 2 switches):
1. The inductive alarms can be supplied as a stand alone option or
combined with the transmitter. Connections to the alarms are made inside
the indicator housing. Refer to Figure 1-7 for stand alone inductive alarm
installation and to Figures 1-6 and 1-8 for installation with the transmitter
combined with the inductive alarms.