E-Stop Safety Relay – Model ES-TA-3D1
4.7 Connection to the Machine to be Controlled
The hookup diagram (Figure 3) shows a generic connection of the ES-TA-3D1 safety
relay’s two redundant output circuits to master stop control elements MSC1, MSC2,
MSC3 and MSC4. A master stop control element is an electrically powered device,
external to the ES-TA-3D1 safety relay, which stops the machinery being controlled by
immediate removal of electrical power to the machine and (when necessary) by
applying braking to dangerous motion (reference ANSI B11.19, section 5.2: “Stop
Control”). This stopping action must be accomplished by removing power to either
master stop control element.
To satisfy the requirements of Safety Category 4 of prEN 954-1, the master stop
control elements must offer a normally closed, force-guided monitor contact. One
normally closed monitor contact from each master stop control element is wired to
the appropriate terminals on the module (see Figure 3). In operation, if any of the
master stop control elements fails to de-energize, the associated monitor contact will
remain open. As a result, it will not be possible to reset the ES-TA-3D1 safety relay.
NOTE: If less than four MSC elements are controlled by the ES-TA-3D1, jumper the
unused monitor inputs to simulate a closed contact. See NOTICE Regarding
MSC Monitor Hookup, at right.
Apply power to the machine control elements and perform the Periodic Checkout
Procedure (see section 5.2).
SECTION 5 – Operating Instructions
5.1 Security Protocol
The ES-TA-3D1 E-Stop Safety Relay should be mounted inside a lockable enclosure.
For security reasons, the key to the lockable enclosure must be in the possession of a
Qualified Person or Persons. A Qualified Person is a person who, by possession of a
recognized degree or certificate of professional training, or who, by extensive
knowledge, training, and experience, has successfully demonstrated the ability to
solve problems relating to the subject matter and work (ANSI B30.2-1983).
The key to the Reset switch (if the Reset switch, as installed, requires a key) should
be available to a Designated Person or Persons. A Designated Person is one who is
identified and designated in writing, by the employer, as being appropriately trained
and qualified to perform a specified checkout procedure. A machine operator who
meets these requirements may be a Designated Person.
CAUTION . . .
Dangerous Voltage
Before performing the
initial checkout
procedure, make certain all power is
disconnected from the machine to
be controlled. Dangerous voltages
may be present along the ES-TA-
3D1 wiring barriers whenever power
to the machine control elements is
“ON”. Exercise extreme caution
whenever machine control power is
or may be present. Always
disconnect power to the machine
control elements before opening
the enclosure housing of the
ES-TA-3D1.
NOTICE Regarding
MSC Monitor Hookup
It is strongly recommended that one
normally closed auxiliary contact of
each Master Stop Control element
(MSC) be wired as an MSC monitor
contact, as shown in Figure 3. If this is
done, any inconsistency of action
between the MSCs will create a fault
condition, which will prevent the
E-stop relay from resetting.
