Seametrics M-Series - Manual (Page 2)

Position. M-Series meters should be installed horizon-
tally with register up. Vertical mounting will result in some
degree of under-measurement and shortened life of the
bearings.
Couplings. Couplings are included with each meter.
These provide male NPT threads the same nominal size
as the meter. The threads on the end of the meter are
IPS straight threads one size bigger than the
meter size. It is possible to thread a standard pipe cou-
pling directly onto the meter for close coupling, but the
meter couplings are much preferable because they pro-
vide a union connection for meter service. Be sure to
use the included gasket between the end of the meter
and the coupling.
Inlet Conditions. No upstream straight pipe is required.
A strainer is built in to protect from solids, and should be
periodically cleaned.
Air Bleed. When the meter is first installed, trapped air
should be removed. To do this, loosen meter couplings
slightly and rotate the meter to an inverted position. Al-
low water to flow, then rotate back to an upright position
and tighten.
Connections. ME and MR sensors are supplied with a
color coded output cable. See the diagram for color
codes and polarity. ME meters come standard with a
specified connector on the end of the cable, to plug di-
rectly into a SeaMetrics control or a specific brand of
metering pump. MR meters can also be ordered with
connectors, if desired.
Pulse Output. Both ME and MR sensors respond to
a magnet which rotates on the face of the meter under
the lens. The sensor turns on and off once each time
the magnet passes under it. There are one and two-
pole magnets. Sensors are designed for electronic
control loads, and should not be used to switch power
loads or line voltages. See maximum current and volt-
age ratings.
Maintenance
Inlet Strainer. Clean the strainer yearly, or as required,
depending on water condition. Pull out the strainer or
backflush the meter to loosen trapped particulates.
Calibration. Meters used for billing or billing exemption
may be regulated by state or local authorities. New
meters are factory-tested to meet the AWWA C-708 Multi-
Jet Meter accuracy specification. Some states
require retesting at various intervals, typically eight years
for 3/4" meters, six for 1", and four for 1-1/2" and 2".
Meters used for control should be tested every 5-10 years.
Testing can be done by local meter shops authorized for
this purpose, or can be done by the factory. For tracking
purposes, please obtain a Returned Material Authoriza-
tion (RMA) number before shipping to SeaMetrics.
Internal Parts Replacement. All of the internal parts of
an M-Series meter lift out as a unit, after the top has
been unscrewed. To remove the meter top, loosen by
putting a bar through the slots on the meter top. Then
remove the lens and lift out the internal assembly. If nec-
essary, turn the meter upside down and tap one end
lightly on a countertop to loosen the internals. The three
pieces of the assembly can be separated by hand.
Breakage in a relatively-new meter is almost always due
to excessive flow. Compare maximum flow with the flow
rating table.
Changing Pulse Rates. After removing the meter top,
remove the magnet by pulling gently with the fingers. To
install a magnet on another shaft, remove the pointer
and then press the magnet down until it bottoms. It is
sometimes necessary to lift the gear below the dial
slightly in order to get the magnet all the way down. Use
the pulse rate chart to determine the position and num-
ber of poles required.
Changing Sensors. Sensors are threaded into the lens
hand tight. Unthread one sensor and thread in the other.
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(BLACK) Power (-)
(BLACK) Common
(WHITE) Signal
(RED) N.O.
(RED) Power (+) 6-24 VDC
ME sensor connection
MR sensor connection
Installation
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