Cut Sheet
© 2016 Littelfuse Protection Relays & Controls
Time Delay Relays
Dedicated - Interval
www.littelfuse.com/tsd7
Rev: 1-A-061016
TSD7 SERIES
L1 N/L2
Interval/Delay-on-Break Timer
Description
The TSD7 Series utilizes only two terminals connected in series
with the load. Interval timing mode period is achieved by using a
small portion of the AC sine wave allowing sufficient voltage for
circuit operation. It can be used as an interval timer to control or
pulse shape the operation of contactors, solenoids, relays, and
lamp loads. The TSD7 Series can be wired to delay on the break
of a switch for energy saving fan delays.
Operation (Interval)
Upon application of input voltage, the output energizes and the
time delay begins. The output remains energized throughout the
time delay. At the end of the time delay, the output de-energizes
and remains de-energized until power is removed.
Reset: Removing input voltage resets the time delay and
the output.
Operation (Delay-on-Break)
Upon closure of SW1, the load is energized and the timer is
reset (zero volts across its input terminals). Opening SW1 re-
applies input voltage to the timer, the load remains energized
and the time delay begins. At the end of the time delay, the
output de-energizes. If SW1 is open when power is applied, the
load will energize for the time delay then de-energize.
Reset: Reclosing SW1 resets the timer.
Features & Benefits
FEATURES BENEFITS
Microcontroller based
Repeat Accuracy + / - 0.5%,
+ / -1% time delay accuracy
Extended
temperature range
Rated to 75°C operating temperature to withstand
high heat applications
Compact, low
cost design
Allows flexiblility for OEM applications
1A steady solid-state
output, 10A inrush
Provides 100 million operations in typical conditions.
Totally solid state
and encapsulated
No moving parts to arc and wear out over time and
encapsulated to protect against shock, vibration,
and humidity
Two terminal series
load connections
Provides quick and easy installation for new or
existing systems
Wiring Diagram
V = Voltage
L = Load
S1 = Initiate Switch
R
T
is used when external
adjustment is ordered.
Interval
Delay-on- Break
Ordering Information
MODEL INPUT VOLTAGE ADJUSTMENT TIME DELAY MODEL INPUT VOLTAGE ADJUSTMENT TIME DELAY
TSD7412S 120VAC Fixed 2s TSD761120S 230VAC Fixed 120s
TSD7414M 120VAC Fixed 4m TSD761180S 230VAC Fixed 180s
TSD7421 120VAC External 1 - 100s TSD7611S 230VAC Fixed 1s
TSD7423 120VAC External 0.1 - 10m TSD7621 230VAC External 1 - 100s
TSD7424 120VAC External 1 - 100m
If you don’t find the part you need, call us for a custom product 800-843-8848