PSSU/1 TAPESWITCH, PSSU/1 Datasheet - Page 2

• Manufacturer Part Number: PSSU/1
• Description: Switch, FAIL SAFE INTERFACE CONTRollerS, 110/240 VAC, DIN RAIL MOUNT
• Manufacturer: TAPESWITCH
• Type: Safetyr

Specifications of PSSU/1

• Application: Medium to high risk safety
• Brand/series: PSSU Series
• Dimensions: 2.95 in. L x 2.2 in. W x 4.3 in. H
• Enclosure Type: DIN Rail Mounted
• Frequency, Operating: 50⁄60 Hz
• Monitor Output: 5 A @ 240 VAC Resistive, Non-Inductive
• Mounting Type: DIN Rail
• Output Contact: 2 x Normal Open, 2A @ 240 VAC Resistive, Non-Inductive
• Output Relays: 2 x Safety Relays Cross Monitored
• Power Consumption: 6 VA
• Primary Type: Controller
• Protection Rating: IP20
• Reset Mode: Manual (Remote)
• Standards: UL, cUL
• Temperature, Operating: 0 to 50 °C
• Time, Response: 20 ms (Max.)
• Voltage, Supply: 110/240 VAC
• Weight: 13 Oz.
• Lead Free Status / Rohs Status: RoHS Exempt Product
• For Use With: Machine Control

INTRODUCTION
PSSU control units are designed to be used with Tapeswitch
pressure-sensitive sensors, such as ribbon switches, sensing
edges, bumpers, and presence-sensing switching mats, to
form a complete safety system. A number of sensors can be
connected in series.
CONTROL UNIT TYPES
Four versions of the control unit are available which differ only
in their type of enclosure and supply voltage. The PSSU/1
control unit is housed in a DIN rail-mounting enclosure with 16
integral terminals and operates from a 110 or 240 Vac supply.
The PSSU/2 control unit uses the same enclosure but operates
on a 24 Vdc supply. Both of the above units are intended to be
fitted inside an existing electrical enclosure on the machine.
This existing enclosure must be sealed to a minimum rating of
IP54.
The PSSU/3 control unit uses a polycarbonate enclosure
sealed to IP67 and operates from a 110 or 240 Vac supply.
The PSSU/4 control unit uses the same IP67 enclosure as the
PSSU/3 unit but operates from a 24 Vdc supply. Both the
above units are intended to be fitted either externally or inside
an existing enclosure on the machine.
SAFETY INTEGRITY
All PSSU control units exceed the requirements of safety
integrity level 2 as defined by DIN 31006-1. The control units
are self-monitoring, which means that any faults in safety
critical components will be detected and will render the
machine inoperative until the fault is rectified. However, the
safety integrity of the system as a whole depends on the safety
integrity of the sensor used, in addition to the proper
installation, interface, and application.
PRINCIPLE OF OPERATION
The control units contain the power supply for the system, the
safety output relays and the reset circuit. Figure 1 shows the
principle of operation. A 24 Vdc power supply is taken from the
control unit to the switching elements in the sensor(s): +v
one conductor, -v
control unit where it supplies power to the output relays.
Release 08/2007 Ver. 2.0
TAPESWITCH CORPORATION
e
to the other conductor, and back to the
PSSU Control Unit
Installation Instructions
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to
1
The output contacts of the safety relays are only closed when
the output relays are energized. When the sensor(s) is
actuated, the 24 Vdc power supply to the output relays is
shorted out causing them to de-energize. Furthermore, if the
power supply to the output relays is interrupted or shorted out
by a fault in the sensor(s) wiring or in the switch elements,
power to the output relays will be lost, the relays will de-
energize and the output contacts will open. The reset circuit
provides start and restart interlock functions as follows:
Start Interlock - When power is applied to the system, the
output relays cannot be energized until a reset signal has been
applied and removed.
Restart Interlock - Once the sensor(s) has been actuated and
the output relays have de-energized, they cannot be energized
again until a reset signal has been applied and removed.
Reset will be prevented while the sensor is actuated, if there is
a fault in the reset input circuit or if the two output relays are in
disparity. The safety output contacts of the control unit are
connected to the machine primary control element(s) in such a
way that if either of the safety output relays is de-energized
then the machine will be brought to rest regardless of the state
of the other relay.
NOTE: A machine primary control element or MPCE is defined
as an electrically-controlled element which directly controls the
normal operating motion of a machine such that it is the last (in
time) to operate when motion is initiated or arrested.
In addition, where the machine control system has two
MPCEs, these devices can be monitored by connecting
normally-closed auxiliary contact from each MPCE in series
with the reset input. Disparity between the two MPCEs will
prevent a reset.
INSTALLATION WARNING
Tapeswitch Safety Systems are designed to protect
operators working at or near dangerous machines. They
can only perform that function if they are correctly fitted
and interfaced to a suitable machine. Every effort has
been made to provide comprehensive and accurate
information. It is the responsibility of the user to ensure
that all persons involved in the installation of the product
have the knowledge, training and experience necessary
and that they are fully conversant with all laws, rules,
regulations and codes of practice at their task.
Installation Instructions: PSSU Control Unit