Ashcroft KM46 Operating Manual

KM46 PRESSURE
TRANSMITTER INSTALLATION
INSTRUCTIONS

m WARNING! READ m

BEFORE INSTALLATION

1. GENERAL:

A failure resulting in injury or dam­age may be caused by excessive

overpressure, excessive vibration
or pressure pulsation, excessive
instrument temperature, corrosion
of the pressure containing parts,
or other misuse. Consult Ashcroft
Inc., Stratford, Connecticut, USA
before installing if there are any
questions or concerns.

2. OVERPRESSURE:

Pressure spikes in excess of the
rated overpressure capability of the
transducer may cause irreversible

electrical and/or mechanical dam­age to the pressure measuring and

containing elements.
Fluid hammer and surges can
destroy any pressure transducer and
must always be avoided. A pressure
snubber should be installed to elim­inate the damaging hammer effects.
Fluid hammer occurs when a liquid
flow is suddenly stopped, as with
quick closing solenoid valves. Surges
occur when flow is suddenly begun,
as when a pump is turned on at full
power or a valve is quickly opened.
Liquid surges are particularly dam­aging to pressure transducers if the
pipe is originally empty. To avoid
damaging surges, fluid lines should
remain full (if possible), pumps should
be brought up to power slowly, and
valves opened slowly. To avoid
damage from both fluid hammer and
surges, a surge chamber should be
installed.

Symptoms of fluid hammer and surge’s
damaging effects:

• Pressure transducer exhibits an
output at zero pressure (large zero
offset).

• Pressure transducer output remains
constant regardless of pressure

• In severe cases, there will be no
output.

FREEZING:

Prohibit freezing of media in pres­sure port. Unit should be drained
(mount in vertical position with elec­trical termination upward) to prevent
possible overpressure damage from
frozen media.

3. STATIC ELECTRICAL CHARGES:

Any electrical device may be sus­ceptible to damage when exposed
to static electrical charges. To avoid
damage to the transducer observe
the following:

• Ground the body of the transducer
BEFORE making any electrical
connections.

• When disconnecting, remove the
ground LAST!

Note: The shield and drain wire in the

cable (if supplied) is not connected
to the transducer body, and is not a
suitable ground.

DESCRIPTION
The Ashcroft Model KM46 pressure
transducer is a high performance
instrument intended for use in applica­tions where the process media is com­patible with Titanium sensor material
and process connection.

MECHANICAL INSTALLATION
Environmental

The KM46 transducer can be stored
within a temperature limit of -40°C to
125°C (-40°F to 257°F) and operated
within a temperature limits of -40°C to
105°C (-40°F to 221°F). IP65 or IP67
(ingress protection) rating applies for
most configurations depending on elec­trical connection, install accordingly..

Mounting
The KM46 transmitter requires no spe­cial mounting hardware and can be
mounted in any orientation with negligi­ble position error. Although the units can
withstand considerable vibration without
damage or significant output effects, it
is always good practice to mount the
transducer where there is minimum
vibration. For units with NPT type pres­sure fittings apply sealing tape or an
equivalent sealant to the threads before
installing. When installing or removing
the unit apply a wrench to the hex wrench
flats, located above the pressure fitting.
DO NOT tighten by using a pipe wrench
on the housing. A 22mm (
be used on the wrench flats of the hex (as
per DIN 894 or similar) with a tightening
torque of ~25Nm (20 ft lbs). For KM46
models with detachable electrical con­nectors a 6 point deep socket can also be
used to install the unit.

Electro-Magnetic Interference
The circuitry of the KM46 transmitter
is designed to minimize the effect of
electromagnetic and radio frequency
interference. To minimize susceptibility
to noise, avoid running the termination
wiring in a conduit which contains high
current AC power cables. Where possi­ble avoid running the termination wiring
near inductive equipment.

Field Adjustments
The KM46 transmitter is precisely cali­brated and temperature compensated
at the factory to ensure long and stable
performance. There are no field accessi­ble adjustments on the KM46 transmitter.

ELECTRICAL INSTALLATION
Please refer to the reverse of this page
for power supply requirements and for
appropriate wiring protocol based on
the particular output signal and electri­cal termination features of the unit being
installed.

7

⁄8˝) wrench can

©Ashcroft Inc., 250 East Main Street, Stratford, CT 06614 USA, Tel: [phone], Fax [phone] www.ashcroft.com
All sales subject to standard terms and conditions of sale. All rights reserved. km46_transducer_im_RevA__Ltr_10-03-18

KM46 PRESSURE

Power Supply Voltage vs. Loop Resistance

(4-20mA ONLY)

Loop Resistance (R

Connections *

nc = not connected

The electrical connection must be made in accordance with the respective

* Custom-made adjustments are possible.

TRANSMITTER INSTALLATION
INSTRUCTIONS

KM46 ELECTRICAL INSTALLATION

Wiring Diagrams

Power Supply Requirements:

Output Signal Min Supply Max Supply

0-10V 12Vdc 32Vdc
0-5V, 1-5V, 1-6V 8Vdc 32Vdc
4-20mA* 10Vdc 32Vdc

* For transmitters with 4-20mA output signal,

the minimum voltage at the terminals is
10Vdc. However, the minimum supply volt­age should be calculated using the adja­cent graph and formula.

Power Supply Voltage vs Loop Resistance

1400

1200

-Ohms)

L

10

(min)

Loop Supply Voltage (Vdc) [LSV]

To determine minimum loop supply voltage:

LSV(min)=9(V)+[.022(A)*RL ]

Where:

LSV= Loop Supply Voltage (Vdc)
RL = RS+ RW (ohms)
RL = Loop Resistance (ohms)
RS = Sense Resistance (ohms) [Measuring Instrument]
RW = Wiring Resistance (ohms)

32 (max)

40

KM46 TERMINATIONS AND WIRING

Plug M12x1Cable port DIN EN DIN EN

4

1

PowerPower PowerPower

1: UB+red : UB+1: UB+1: UB+
2: nc black: out2: out2: out
3: outwhite: nc 3: nc 3: nc
4: nc

VoltageVoltage VoltageVoltage

1: UB+red: UB+1: UB+1: UB+
2: nc black: UB-2: UB-2: UB­3: UB- white: out3: out3: out
4: out

connectiondiagram unless otherwise agreed upon.

3

2

175301-803-A 175301-803-C

1

3

2

1

3

2

©Ashcroft Inc., 250 East Main Street, Stratford, CT 06614 USA, Tel: [phone], Fax [phone] www.ashcroft.com
All sales subject to standard terms and conditions of sale. All rights reserved. km46_transducer_im_RevA_Ltr_10-03-18