Brooks Ar-Mite MT3750, Installation & Operation Manual

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Section 1 Introduction
Brooks
®
Ar-Mite
TM
MT3750C Brooks
®
Ar-Mite
TM
MT3750C
6
Reed Switch Alarm
Two reed switches are installed in the alarm housing to provide signaling or
switching functions when a preset flow value has been reached. The reed
switches provide high, low or dual setpoints and latched output over the
full range. The switches are normally adjusted to the desired flow range in
the factory. Modifications to the switch settings can be made in the field.
Minimum setting distance between two switches is approximately 40% of the
scale. (Reference Reed Switch Wiring Diagram Figure 1-5)
Data Reed Switch
Maximum Voltage* 175 Vdc, 124 Vac
Maximum Current* 250 mA
Maximum Contact Rating* 3 Watts
(*Maximum Switch Specifications)
Electrical Classification
Non Incendive:
Maximum Voltage 30 Vdc
Maximum Current 100 mA
Maximum Contact Rating 3 Watts
Table 1-8 Approvals - MT3750C With Reed Switch Alarm
Figure 1-4 Model MT3750C with
Reed Switch Alarm
Figure 1-5 Reed Switch Wiring Diagram
Mechanical Tr
an
smi
tte
r
Indu
cti
ve
Switch
Alar
m
Reed Switch Alar
m
Explosion safety
"Intrinsic Safety (ia)"
1788748
Explosion safety
"Non-incendive"
1788748
Explosion safety
"Intrinsic Safety (ia)"
Class I, Div 1, Groups A, B, C and D; Class II, Groups E, F and G; Class
III; Encl Type 4X
IS Entity Parameters: Vmax=30Vdc, Imax=100mA, Ci=0, Li=0
Class I, Div 2, Groups A, B, C and D; Class II, Groups E, F and G; Class
III; Encl Type 4X
Reed Switch Alarms are classified as “Simple Apparatus” when used in Intrinsically Safe circuits.
They comply with the requirements of EN60079-11 clause 5.7 – Simple apparatus.
Ambient Temperature ratings: -20° C ≤ Tamb ≤ 65° C
Input parameters: Vmax = 30V, Imax = 100mA, Ci = 0μF, Li = 0μH
Special conditions for safe use:
• The product should be installed by suitably trained personnel, in accordance with the applicable
code of practice.
• As the product has no source of internal heating, the temperature classification is dependent on the
ambient air temperature.
• Since part of flowmeter enclosure is made of painted aluminum, if it is mounted in group II, category
1 area, it must be installed such, that, ignition sources due to propagating brush discharge spar ks are
excluded
Table x-xx Product Approvals - 3750 With Reed Switch Alarm
Approvals Mark
Meter Options
Standards/Directives/Marking Declaration/Certificate