Brooks Instrument 3750 - Manual (Page 12)

1-6
Installation and Operation Manual
X-VA-MT3750C-eng
Part Number: 541B063AAG
April, 2014
Brooks ® Ar-Mite TM MT3750C
Section 1 Introduction
Figure 1-2 Reed Switch Wiring Diagram
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, refer
to Section 3-4. Minimum setting distance between two switches is
approximately 40% of the scale. (Refer to Figures 1-2 and 1-3)
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
CSA (US and Canada)
NI Class I, Div. 2, Groups A, B, C and D:
Class II Groups F and G, T6
per CSA-213: 1987; UL 1604; 1995
Intrinsic Safety:
Entity parameters
Vmax = Ui = 30 Vdc, Imax = Ii = 100 mA, Ci = 0, Li = 0
CSA: (US and Canada)
IS Class I, II, III, Div. 1, Groups A thru G, T6
per CSA-157:1992; UL 913:2002