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PT-AMR limit switch
instrumentation
for fluids
For series PT, PTM,
PS, PSM and 6000
Instructions manual
R-MI-PTAMR Rev.:4
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INTRODUCTION
The PT-AMR is a magnetically operated bi-stable reed switch, operated by the magnet in the
flowmeter’s float. The limit switch can be supplied as a normally open switch when the float is
below the switch (PT-AMR NA), or as a normally closed switch (PT-AMR NC).
PTM / PSM
DN 15 20
½" ¾"
A 47 52
PT / PS
DN 15 20 25 40 50 65 80
½" ¾" 1" 1½" 2" 2½" 3"
A 47 52 62 70 70 90 90
6000
DN 15-20 20-25 40(1) 40(2) 50 65-80
½"-¾" ¾"-1" 1½" 1½" 2" 2½"-3"
A 48 51.5 61 67.5 80 94
ELECTRICAL CONNECTION
For the electrical installation, a multi-conductor cable should be used to obtain a good seal with
the cable gland. The connector is provided with a PG 9 cable gland, suitable for a 4.5 to 7 mm
outside diameter cable. Terminals 1 and 2 of the connector are connected to the two ends of the
reed switch.
In the female connector:
Terminal 1: Reed switch contact
Terminal 2: Reed switch contact
2
1
Terminal 3: No connection
Earth terminal: No connection
3
2
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Make sure that the contact rating is not exceeded. If high loads are to be switched, use an
auxiliary relay.
When using inductive loads, such as relays or electro‑valve coils, surge arresters should be
installed to protect the reed contacts.
With a DC supply, a di o d e s h ou l d be c on n e ct e d a s s h ow n .
For an AC supply, a RC circuit can be used as shown, although a varistor (VDR) is better and is
easier to select the right value. The VDR should have a breakdown voltage greater than 1.5 times
the rms voltage. The standard varistor ratings specify the rms working voltage for the varistor, for
example a S05K25 varistor will be for 25 Vrms working and will have a breakdown voltage of 39 V
at 1 mA.
The electrical installation should provide
a fuse or circuit breaker to protect the
reed switch from overloa ds.
When i n st a l l in g t h e connector, m a ke
sure that the cable gland (A) closes
over the cable and that the connector
(B) with the rubber seal (C) is we ll
screwed down to maintain the IP65
rating.
A
B
C
D
E
OPERATION
To install the PT-AMR on the flowmeter, loosen the screw (E) and clamp the limit switch on the
guide opposed to the reading scale. The position of the reading point of the float with reference to
the PT-AMR, when the switch acts, will vary from one type of float to another. With the float in a
stable position, slide the PT-AMR along the guide until the reed switch changes over. Mark the
position of the reading point of the float on the PT-AMR and then situate this mark at the required
switching level on the scale. Tighten the clamping screw (E).
If the limit switch must be changed from a PT-AMR NC to a PT-AMR NA or vice-versa, first
remove the female connector (B) and the rubber seal (C). Remove the 4 screws that hold the
male connector (D), withdraw the connector, rotate it 180º and then reassemble the complete unit,
taking care that the seals are properly fitted to maintain the ingress protection.
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MAINTENANCE
No spe c i al maintenance is re q u i re d .
TECHNICAL CHARACTERISTICS
Standard DIN 43650 connector
Contact Rating:
Maximum Switching Power: 12 VA
Maximum Switching Voltage: 250 VAC
Maximum Switching Current: 0.5 A
Working Conditions:
Ingress protection: IP65
Ambient Temperature: -20 ºC to +80 ºC
Conforms with the Directive 73/23/EC
WARRANTY
Tecfluid S.A. GUARANTEES ALL ITS PRODUCTS FOR A PERIOD OF 24 MONTHS, after
consignment, against all defects in materials and workmanship.
This warranty does not cover failu res which can be imp uted to mis use, use in an application different
to that specified in the order, the result of service or modification by un-authorized persons, bad
handling or accident.
This warranty is limited to cover the repair or replacement defective parts which have not been
damaged by misuse.
This warranty is limited to the repair of the equipment and all further and eventually following
damages are not covered by this warranty.
Any consignment of equipment to our factory or distributor must be previously authorised. The
consignment should be done with the equipment well packed, clean of any liquids, grease or
hazardous materials.
Together with the equipmen t, a note should be enclosed indicating the failure observ ed, the name,
address and telephone number of the sender.
SHIPPING
In the event of damages during shipping, claim directly to the carrier over a period of less than 24
hours. Tecfluid is not responsible for any damage caused during the shipment of material.
TECFLUID, S.A.
Narcís Monturiol, 33
E-08960 Sant Just Desvern
Tel. + 34 93 3724511 - Fax + 34 93 4734449
E-mail: [email protected]
Internet: www.tecfluid.com
The technical data in this document is subject to modification without notification, if the technical innovations in the product or
manufacturing processes so require.
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