Instruction Leaflet
30-470 (E)
Page 8
Automatic Control (Continued)
When adjustable type voltage sensors have been ordered, they are
factory set to dropout at 90 volts and pickup at 108 volts Ac. For
adjustment to other settings, first set the drop value and adjust the
pickup to desired setting. This is done by using a variable power
supply for the coil, pins 2 and 7, and using an ohm meter on the
contacts to determine when the relay has picked-up.
Additional relays are available for over voltage monitoring, emergency
source monitoring, and 125 volt Dc applications.
Note: The pickup and dropout settings do vary with temperature
variations at a rate of 0.1% per degree C from a nominal operating
temperature of 25°C.
On Delay Time Delay Relays
Ratings 6 Watts Power Consumption
Input coil Voltage 120 Volts
Contact Rating 3 amperes at 220 volts Ac 50/60 Hertz
Operating Temperature Rating -10°C to +50°C
Time Ratings Various available
Description
This time delay relay is an octual plug-in, synchronous motor type. It is
complete with clutch and mechanical load switch giving one instanta-
neously operated normally open contact and a timed single pole double
throw contact in a dust-tight grey capsule. The mechanism is
constructed to operate for the time set on the indicating dial and then
disconnect itself when the timing cycle is complete. A red pilot light on
the face plate indicates that the relay is timing to operate its contacts.
When de-energized, the relay requires a reset time of at least 0.5
seconds. Time delay begins immediately upon energizing the coil.
When the timing cycle is complete, a mechanical latch holds the
contacts in position and the coil is de-energized.
Application
The time delay relay is used on the Robonic Automatic Transfer
Switch for four functions. They are designated as EN, NE, EC and DT.
It may also be used for additional timing functions if required.
When used as an EN device, it is incorporated into the control scheme
to delay the operation of the transfer switch to the normal position,
and prevent the transfer on momentary return of the normal power
source. Upon restoration of the normal source it begins timing and
should the source fail again prior to completing the timing cycle, the
relay will reset to time again. If the normal power source should
remain restored longer than the timing cycle the EN will open its
normally closed contact in the control relay, CR, initiating re-transfer.
When used as an NE device, it is incorporated into the control scheme
to delay the transfer to the emergency position until the normal source
has failed longer than the time setting. This allows the standby source
time to stabilize prior to transfer. When the time cycle is complete, it
closes its contact in the control relay, CR, initiating transfer.
When used as an EC device, it is incorporated in the control scheme to
delay the stopping of the standby source after re-transfer. The
standby will run unloaded to cool off for the set timing cycle. When the
cycle is complete, it closes its contact in the engine start relay, ES,
which in turn stops the standby unit. If the normal power should fail
again prior to completing the timing cycle, the transfer switch will
transfer again instantly.
When used as a DT device, it is incorporated in the control scheme to
stop the transfer switch with both breakers open. This is to allow
residual load voltage to decay prior to closing on another supply
which could be out of phase. When the timing cycle is complete, the
relay re-initiates transfer to the available source.
OFF Delay Time Delay Relays
Pneumatic Type
Ratings 8 Watts Power Consumption
Input Coil Voltage 120 volts 50/60 Hertz
Contact Rating 10 amperes resistive at 120 volts Ac
Time Ranges Various available
Operating Temperature Range -30r°C to +75°C
Description
This is a panel mount relay containing a coil, an adjustable sealed
pneumatic timing head and snap action switch assembly. The relay will
pick up instantaneously when the voltage is applied to the coil and it
will remain in this position as long as the coil is energized. Time delay
begins immediately upon de-energization and at the end of the timing
cycle, the switch returns to its de-energized position. Reenergizing
the coil during the timing cycle will reset the relay to time a complete
cycle again.