© 2016 Littelfuse Protection Relays & Controls
Time Delay Relays
Dedicated - Delay-on-Break
www.littelfuse.com/hrdb
Rev: 1-A-062116
HRDB SERIES
Delay-on-Break Timer
Description
The HRDB Series combines an electromechanical, relay output
with microcontroller timing circuitry. The HRDB offers 12 to 230V
operation in five options and factory fixed, external, or onboard
adjustable time delays with a repeat accuracy of ±0.5%. The
isolated output contact rating allows for direct operation of heavy
loads, such as compressors, pumps, blower motors, heaters, etc.
The HRDB is ideal for OEM applications where cost is a factor.
Operation (Delay-on-Break)
Input voltage must be applied before and during timing. Upon
closure of the initiate switch, the output relay energizes. The
time delay begins when the initiate switch is opened. The output
remains energized during timing. At the end of the time delay,
the output de-energizes. The output will energize if the initiate
switch is closed when input voltage is applied.
Reset: Reclosing the initiate switch during timing resets the time
delay. Loss of input voltage resets the time delay and output.
Features & Benefits
FEATURES BENEFITS
Microcontroller based Repeat Accuracy + / - 0.5%
Compact, low
cost design Allows flexiblility for OEM applications
Isolated, 30A, SPDT,
NO output contacts
Allows direct operation of heavy loads:
compressors, pumps, blower moters, heaters.
Accessories
P1004-95, P1004-95-X Versa-Pot
Panel mountable, industrial potentiometer
recommended for remote time delay adjustment.
P1023-6 Mounting bracket
The 90° orientation of mounting slots makes
installation/removal of modules quick and easy.
P0700-7 Versa-Knob
Designed for 0.25 in (6.35 mm) shaft of
Versa-Pot. Semi-gloss industrial black finish.
V = Voltage
S1 = Initiate Switch
L = Timed Load
UTL = Untimed Load (optional)
NO = Normally Open
C = Common, Transfer Contact
NOTE: A knob, or terminals
4 & 5 are only included on
adjustable units. RT is used
when external adjustment
is ordered. Relay contacts
are isolated. Dashed lines
are internal connections. The
untimed load is optional.
Wiring Diagram
L1 N/L2
Ordering Information
MODEL INPUT
VOLTAGE ADJUSTMENT TIME
TOLERANCE TIME DELAY MODEL INPUT
VOLTAGE ADJUSTMENT TIME
TOLERANCE TIME DELAY
HRDB1110M 12VDC Fixed + / -5% 10m HRDB223 24VAC Onboard + / -5% 0.1 - 10m
HRDB117S 12VDC Fixed + / -5% 7s HRDB321 24VDC Onboard + / -5% 1 - 100s
HRDB120 12VDC Onboard + / -5% 0.1 - 10s HRDB324 24VDC Onboard + / -5% 1 - 100m
HRDB121 12VDC Onboard + / -5% 1 - 100s HRDB423 120VAC Onboard + / -5% 0.1 - 10m
HRDB124 12VDC Onboard + / -5% 1 - 100m HRDB623 230VAC Onboard + / -5% 0.1 - 10m
HRDB21A65M 24VAC Fixed + / -1% 65m
If you don’t find the part you need, call us for a custom product 800-843-8848
© 2016 Littelfuse Protection Relays & Controls
Time Delay Relays
Dedicated - Delay-on-Break
www.littelfuse.com/hrdb
Rev: 1-A-062116
HRDB SERIES
Specifications
Time Delay
Type Microcontroller circuitry
Range 0.1s - 100m in 5 adjustable ranges or fixed
Repeat Accuracy ±0.5 % or 20ms, whichever is greater
Tolerance
(Factory Calibration) ±1%, ±5%
Reset Time ≤ 150ms
Initiate Time ≤ 20ms
Time Delay vs Temp.
& Voltage ±2%
Input
Voltage 12 or 24VDC; 24, 120, or 230VAC
Tolerance
12VDC & 24VDC -15% - 20%
24 to 230VAC -20% - 10%
AC Line Frequency 50/60 Hz
Power Consumption AC ≤ 4VA; DC ≤ 2W
Output
Type Electromechanical relay
Form Isolated, SPDT
Ratings SPDT-NO SPDT-NC
General Purpose 125/240VAC 30A 15A
Resistive 125/240VAC 30A 15A
28VDC 20A 10A
Motor Load 125VAC 1 hp* 1/4 hp**
240VAC 2 hp** 1 hp**
Life Mechanical - 1 x 106;
Electrical - 1 x 105, *3 x 104, **6,000
Protection
Surge IEEE C62.41-1991 Level A
Circuitry Encapsulated
Dielectric Breakdown ≥ 2000V RMS terminals to mounting surface
Insulation Resistance ≥ 100 MΩ
Polarity DC units are reverse polarity protected
Mechanical
Mounting Surface mount with one #10 (M5 x 0.8) screw
Dimensions H 50.8 mm (2”); W 50.8 mm (2”);
D 38.1 mm (1.51”)
Termination 0.25 in. (6.35 mm) male quick connect terminals
Environmental
Operating/Storage
Temperature -40° to 60°C / -40° to 85°C
Humidity 95% relative, non-condensing
Weight ≅ 3.9 oz (111 g)
Accessories
P1015-13 (AWG 10/12), P1015-64 (AWG 14/16)
Female Quick Connect
These 0.25 in. (6.35 mm) female terminals are
constructed with an insulator barrel to provide
strain relief.
P1015-18 Quick Connect to Screw Adapter
Screw adapter terminal designed for use with
all modules with 0.25 in. (6.35 mm) male quick
connect terminals.
C103PM (AL) DIN Rail
35 mm aluminum DIN rail available in a 36 in.
(91.4 cm) length.
P1023-20 DIN Rail Adapter
Allows module to be mounted on a 35 mm DIN
type rail with two #10 screws.
External Resistance vs. Time Delay
Function Diagram
DELAY-ON-BREAK (OFF-DELAY) V = Voltage
S1 = Initiate Switch
NO = Normally
Open Contact
NC = Normally
Closed Contact
TD = Time Delay
t = Incomplete
Time Delay
R = Reset
= Undefined
Time
