Form 859-990514

SOLID-STATE RELAYS

DATA SHEET

page 10/12

Opto 22 • 43044 Business Park Drive • Temecula, CA 92590 • Phone: (909)695-3000 • (800)321-OPTO • Fax: (909)695-3095 • Internet: www.opto22.com

Inside Sales:(800)452-OPTO •Product Support: (800)TEK-OPTO•(909)695-3080•Fax:(909)695-3017 •E-mail:support@opto22.com•FaxBack:(800)474-OPTO

Transformer Loads

Solenoid Valve and Contactor Loads

Careful consideration should be given to the selection

oftheproperSSRfordrivingagiventransformer. Transformers

aredrivenfrompositivesaturationoftheironcoretonegative

saturation of the core each ½ cycle of the alternating

voltage.Largeinrushcurrentscanoccurduringthefirst½cycle

of line voltage when a zero voltage SSR happens to turn on

during the positive ½ cycle of voltage when the core is

already in positive saturation. Inrush currents greater than

10 times rated transformer current can easily occur.

The following table provides a guide for selecting the

proper SSR for a given transformer rating.

All Opto 22 SSRs are designed to drive inductive loads such as solenoid

valvesandelectromechanicalcontactors.Thebuilt-insnubberineachSSR

assures proper operation into inductive loads. The following table is a

guide in selecting an SSR to drive a solenoid or contactor.

Tips (Continued)

Applications

Control Current Calculation

All Opto 22 DC controlled SSRs have a control circuit consisting of 1000 ohms in

series with an LED. Since 3 volts is required to turn on any SSR, the maximum current

requiredis(3volt-1volt)dividedby1000ohmswhichequals2.0mA.The1voltissubtracted

fromthe3voltsignalbecause1voltisdroppedacrosstheLED.Forhighercontrolvoltages,

an external resistor can be added in series with the control voltage to limit the control

current. To limit the control current to 2 mA, calculate the external resistor R

where E

The DC control voltage range is 3–32 VDC. To calculate the control current for any

voltage within the 3–32 VDC range, use the formula:

E

1000

I

where R

With a 5V control signal,

I

= 4 mA.

5 - 1

1000

120-Volt Coils

SSR CURRENT

RATING

SOLENOID

CONTACTOR

2-Amp

1-Amp

NEMA Size 4

4-Amp

3-Amp

NEMA Size 7

240-Volt Coils

SSR CURRENT

RATING

SOLENOID

CONTACTOR

2-Amp

1-Amp

NEMA Size 7

4-Amp

3-Amp

NEMA Size 7

120-Volt Transformers

SSR MODEL

TRANSFORMER

P or MP 120D2

100 VA

Z120D10

500 VA

120D3

100 VA

P or MP 120D4

250 VA

120D10 or 120A10

500 VA

120D25 or 120a25

1 KVA

120D45

2 KVA

240-Volt Transformers

P or MP240D2

200 VA

7240D10

1 KVA

120D3

200 VA

P or MP240D4

500 VA

240D10 or 240A10

1 KVA

240D25 or 240A25

2 KVA

240D45

4 KVA

480-Volt Transformers

SSR MODEL

TRANSFORMER

480D10-12

5-Amp Primary

480D15-12

5-Amp Primary