|
ROBERTSHAW VIBRATION SWITCH UNITS
MODEL
365A
FM Approved, CSA Certified
The Model 365
Vibraswitch is an acceleration sensitive instrument that measures the
total peak vibratory shock (destruction forces) present at the point of
measurement. The instrument's explosion proof housing meets Class I,
Division 1, Groups C and D, and Class II, Division 1, Groups E, F and G
hazardous area classifications. It is FM approved and CSA certified. The
instrument provides electrical switch contact closures for on-off control
of alarms and shut-down of machines. Both SPDT and DPDT contact
arrangements are available.
The
set-point is provided with a dial calibrated in 0.1 G divisions. The
instrument has a range of 0 to 4.5 G in a frequency range of 0 to 300 Hz.
The set-point adjustment resolution is 1 G per turn. The Vibraswitch can
be supplied with an electrical reset coil for remote resetting; it is
available for voltages of 24, 48, 120VDC or 120 VAC. A
The
Model 365 Vibraswitch is an acceleration sensitive instrument that
measures the total peak vibratory shock (destruction forces) present at
the point of measurement. The instrument's explosion proof housing meets
Class I, Division 1, Groups C and D, and Class II, Division 1, Groups E, F
and G hazardous area classifications. It is FM approved and CSA certified.
The instrument provides electrical switch contact closures for on-off
control of alarms and shut-down of machines. Both SPDT and DPDT contact
arrangements are available.
The
set-point is provided with a dial calibrated in 0.1 G divisions. The
instrument has a range of 0 to 4.5 G in a frequency range of 0 to 300 Hz.
The set-point adjustment resolution is 1 G per turn. The Vibraswitch can
be supplied with an electrical reset coil for remote resetting; it is
available for voltages of 24, 48, 120VDC or 120 VAC. A
MODEL
366
CSA Certified
The Model 366
Vibraswitch is an acceleration sensitive instrument that measures the
total peak vibratory shock (destruction forces) present at the point of
measurement. The instrument is housed in a general purpose,
weather-resistant enclosure meeting NEMA type 4 specs. The cover is ABS
high impact thermoplastic material and the base is aluminum 360 (Cu Free).
The Model 366 is CSA certified. It provides electrical switch contact
closures for on-off control of alarm and / or shut-down of machines. It is
available with SPDT or DPDT contact arrangements.
The
set-point is provided with a dial calibrated in 0.1 G divisions. The
instrument has a range of 0 to 4.5 G in a frequency range of 0 to 300 Hz.
The set-point adjustment resolution is 1 G per turn. The Vibraswitch can
be supplied with an electrical reset coil for remote resetting; it is
available for voltages of 24, 48, 120 VDC or 120VAC. A manual reset button
is supplied as standard equipment on all units.
MODEL EURO 366 VIBRATION SWITCH
The Model EURO 366 Vibration Switch is primarily
intended for indoor and outdoor hazardous and nonhazardous areas in those
countries requiring ATEX and CE certifications. The EURO 366 employs the
same time proven switch design found in Robertshaw's family of vibration
switches.
The Model EURO 366
Vibration Switch is a vibration sensitive device that protects rotating
and reciprocating machinery from extensive damage resulting from
mechanical malfunction. When the vibration level of a Vibration Switch
protected machine exceeds normal by a preselected amount, the normally
open contacts of an internal switch close and the normally closed contacts
open. This can be used to actuate either an audible warning system or a
shutdown circuit before costly damage occurs Failing bearings, broken
blades and similar
malfunctions cause
increased imbalance or high frequency vibration detectable with the
Vibration Switch. It is designed for
maintenance-free
service in permanent installations.
The Vibration
Switch is an acceleration sensitive instrument that measures the total
acceleratory shock present on the machine. Acceleration is a vibration
characteristic of prime importance in cases of
mechanical failure
on reciprocating or rotating machinery. Acceleration is directly related
to the shock
forces (impact)
acting on a machine - thus the Vibration Switch offers a valid measurement
of the
destructive forces
acting on the machine.
Accelerator
measurements made by the Vibration Switch are the summation of all
of the
individual
accelerations giving a total destructive force acting on the
machine - the result is positive
protection.
MODEL
368 PNEUMATIC VIBRATION SWITCH
VIBRATION PROTECTION USING PNEUMATIC POWER
The
Robertshaw Model 368 Vibraswitch is a pneumatically powered detector for
use on machines where electrical power is not available. This instrument
is particularly well suited to installation in hazardous (explosive)
areas (even in extreme hazard such as hydrogen atmospheres) since only
compressed air is required for its alarm and/or control operation. It does
not require explosion-proof housings. The instrument is also well suited
for applications at pipeline compressor stations and skid-mounted
compressors since it will operate on either natural gas or compressed air.
The
Model 368 is identical to the Model 365/366 Vibraswitch in its principle
of operation as described in this bulletin: refer to Figure 4 for its
basic operation.
OPERATION OF THE PNEUMATIC VIBRASWITCH
When
the instrument is subjected to vibration perpendicular to the base, the
resultant vibratory intertial force, aided by the adjusting spring, pulls
the armature away from the hold-down magnet. Magnitude of this inertial
force is proportional to the mass of the armature and the acceleration
component of the vibratory motion. F = MA where force (F) is equal to mass
(M) times acceleration (A). Refer to Figure 8 for the basic pneumatic
diagram of the Model 368 Vibraswitch.
When
the peak acceleration exceeds the set-point level, the armature breaks
away from the stop pin. moving the trip plunger upward to open the
pneumatic valve, which is normally closed maintaining a 20 psig pressure:
on opening, the inlet (controlled) line pressure drops to 3 psig or lower.
The
pneumatic valve vents into the sealed cover and out the exhaust (vent)
port. The decrease in control pressure is used to actuate a pneumatic
relay which will initiate alarm or shutdown of the malfunctioning
equipment.
When
the instrument is subjected to vibration perpendicular to the base, the
resultant vibratory intertial force, aided by the adjusting spring, pulls
the armature away from the hold-down magnet. Magnitude of this inertial
force is proportional to the mass of the armature and the acceleration
component of the vibratory motion. F = MA where force (F) is equal to mass
(M) times acceleration (A). Refer to Figure 8 for the basic pneumatic
diagram of the Model 368 Vibraswitch.
When
the peak acceleration exceeds the set-point level, the armature breaks
away from the stop pin. moving the trip plunger upward to open the
pneumatic valve, which is normally closed maintaining a 20 psig pressure:
on opening, the inlet (controlled) line pressure drops to 3 psig or lower.
The
pneumatic valve vents into the sealed cover and out the exhaust (vent)
port. The decrease in control pressure is used to actuate a pneumatic
relay which will initiate alarm or shutdown of the malfunctioning
equipment.
|
