Technical information
Cautions for Use of SSR
12
ds_x61_en_ssr_technical_information: 011212D
Load Type Description
Choosing the Rated Voltage of the
ZNR
(1) Peak supply voltage
(2) Supply voltage variation
(3) Degradation of ZNR characteristic
(1 mA10%)
(4) Tolerance of rated voltage (10%)
For application to 100 V AC lines, choose
a ZNR with the following rated voltage:
(1) (2) (3) (4) =
(1002) 1.11.11.1 = 188 (V)
Example of ZNR (Panasonic Electronic Components)
Types
Varistor voltage
Max. allowable circuit
voltage
Max. control
voltage
Max. average
pulse electric
power
Withstanding energy Withstanding surge current
Electrostatic
capacitance
(Reference)
(10/1000s) (2ms) 1time
(8/20s)
2time
V1mA (V) ACrms (V) DC (V) V50A (V) (W) (J) (J) (A) (A) @1KHz (pF)
ERZV14D201 200 (185 to 225) 130 170 340 0.6 70 50 6,000 5,000 770
ERZV14D221 220 (198 to 242) 140 180 360 0.6 78 55 6,000 5,000 740
ERZV14D241 240 (216 to 264) 150 200 395 0.6 84 60 6,000 5,000 700
ERZV14D271 270 (247 to 303) 175 225 455 0.6 99 70 6,000 5,000 640
ERZV14D361 360 (324 to 396) 230 300 595 0.6 130 90 6,000 4,500 540
ERZV14D391 390 (351 to 429) 250 320 650 0.6 140 100 6,000 4,500 500
ERZV14D431 430 (387 to 473) 275 350 710 0.6 155 110 6,000 4,500 450
ERZV14D471 470 (423 to 517) 300 385 775 0.6 175 125 6,000 4,500 400
ERZV14D621 620 (558 to 682) 385 505 1,025 0.6 190 136 6,000 4,500 330
ERZV14D681 680 (612 to 748) 420 560 1,120 0.6 190 136 5,000 4,500 320
WL
3.0 max.
.118 max.
T
.031 dia.
0.8 dia.
20.0 min.
.787 min.
H
D
D:
T:
H:
W:
17.5 dia. max.
6.5 max.
20.5 max.
7.5±1
(mm inch)
.689 dia. max.
.256 max.
.807 max.
.298±.039
2. Over-Current Protection
An SSR circuit operated without over-
current protection may result in damage
to the device. Design the circuit so the
device’s rated junction temperature is not
exceeded for a continuous overload
current.
(e.g. Surge current into a motor or light
bulb)
The surge-on current rating applies to
over-current errors which occur less than
several tens of times during the service
life of a semiconductor device. A
protection coordination device is required
for this rating.
Methods of over-current protection
include the following:
(1) Suppressing over-currents
Use a current limiting reactor in series
with the load power supply.
(2) Use a current shut-off device
Use a current limiting fuse or circuit
breaker in series with the load power
supply.
Example of executing fuse selection
of over-current protection cooperation
10
No. of cycles at 60Hz
Fuse cut-off current
Surge ON current
10
100
1,000
1
100 1,000
(A peak)
NHR15 (fuse 15A)
AQR (15A type)
NHR10 (fuse 10A)
1. Heaters (Resistive Load)
The SSR is best suited to resistive loads.
Noise levels can be drastically lowered
with zero-crossing switching.
2. Lamps
Tungsten or halogen lamps draw a high
inrush current when turned on
(approximately 7 to 8 times the steady-
state current for zero-crossing SSRs;
approximately 9 to 12 times, in the worst
case, for random type SSRs). Choose an
SSR so the peak of the inrush current
does not exceed 50% of the SSR surge-
on current.
3. Solenoids
AC-driven solenoid contactors or
solenoid valves also draw inrush current
when they are activated. Choose an SSR
such that the peak of the inrush current
does not exceed 50% of the SSR surge-
on current. For small solenoid valves and
AC relays in particular, a leakage current
may cause the load to malfunction after
the SSR turns off. In such an event, use a
dummy resistor in parallel with the load.
• Using an SSR below the Specified Load
Load power
supply
Load
SSR Output
Dummy resistor