 
 			  SPR-44 Quad Pulse Isolation Relay
The SPR-44 quad pulse isolation relay is designed to provide four isolated dry-contact, solid state Form C, or KYZ outputs, from four Form A or C inputs. The primary application for the SPR-44 is when four independent isolation relay channels are desired in one package. A variety of pulse splitting relaying schemes can be accomplished by paralleling two or more inputs..
The SPR-44 operates over the  standard SSI wide voltage range. The SPR-44 has a built-in low voltage  transformer-isolated power supply generating a +13VDC wetting voltage. The  sense voltage is sent to each meter’s Y and Z terminals from the SPR-44’s “Yin”  and “Zin” input terminals, returning to the “Kin” terminal, the common return  for all meters. Since all meters supplying pulses to the SPR-44 have a common  reference, a number of flexible input configurations can be wired. For example,  two inputs can be wired in parallel giving a “splitting” configuration where  one input and two outputs is desired. 
The SPR-44 may be used with electric  meters having electro-mechanical or semiconductor dry-contact output contacts,  either high or low voltage. The SPR-44’s inputs are configured to also accept open-collector  transistor or open-drain FET solid state pulse initiator switches. Typical applications  include interfaces between utility metering devices and customer-owned energy  control systems, demand recorder applications, and supervisory control systems  (SCADA) interfaces. The SPR-44 relay is designed for high speed pulses and can  switch up to 72,000 pulses/hour in 3-Wire mode and 36,000 pulses/hour in 2-Wire  mode. The outputs are non-latching. The SPR-44 outputs’ pulse timing follows  the inputs’ timing such that output pulses have the exact same pulse width as  the input.
			        
The  SPR-44 also has a pulse conversion capability built in.  Each of the four channels of the SPR-44 can  be independently set for Normal or Conversion mode.  In the pulse conversion mode, a 3-wire (Form C) input can be converted to a 2-Wire (Form A) pulse while maintaining the same pulse value. Additionally, a 2-wire (Form A) input can be  converted to a 3-Wire (Form C) pulse while maintaining the same pulse value. 
			        
Bright red and green LED indicators,  one of each on every input, indicates each channel’s relay status at all times  thus allowing a rapid check of the system’s performance without requiring any  additional test equipment. The SPR-44’s input and output terminal strip is a  “EURO” type connector. When the stripped wire has been correctly installed in  the terminals “slot” no conductive parts are exposed on the surface of the  terminal strip, thus allowing the user maximum protection from accidental  electrical shock. Each “K” lead of the SPR-44’s four outputs is fused to  prevent damage to the relays under almost any condition a user might cause such  as excessive current, incorrect wiring, etc. 
				      
The SPR-44 has built-in MOV transient protection for the solid state relay contacts which eliminates the need for external or off-board transient suppressors. All component parts which have power applied to them, with the exception of the input/output terminal strip are enclosed in a polycarbonate cover for maximum protection.
The mounting base plate is also made of polycarbonate and offers excellent electrical insulation between the circuits and the mounting surface.| Electrical | |
|---|---|
| Power Input: | 120 VAC to 277 VAC. Burden: 10 mA at 120 VAC | 
| Signal Input: | Each input has “Yin” and “Zin” terminals wetted "pulled up" with +13VDC. “Kin” terminal is the common return. The Form A input uses the “Yin” terminal; the Form C input uses the “Yin” and “Zin” terminals for the input from the meter. | 
| Output: | Four sets of dry Form C contacts (K, Y, & Z) for energy pulses. The relay contacts are solid state with “no bounce” circuitry. Outputs are rated at 125VAC/VDC 1/10th Amp(100 milliamps). Factory fused at 1/10 amp @ 250VAC. (3AG) | 
| Contact On-State Resistance: | 25 ohms maximum, 18 ohms typical | 
| Operate and Release Time: | 2 to 3 milliseconds typical | 
| Input/Output Isolation Voltage: | 3750Vrms | 
| Mechanical | |
|---|---|
| Mounting: | Any position | 
| Size: | 3.50” wide, 7.20” high, 1.50” deep | 
| Weight: | 12 ounces | 
| Temperature | |
|---|---|
| Temperature Range: | -38º C to +70º C, -38.4º F to +158º F | 
| Humidity: | 0 to 98% non-condensing | 
| Available Options | |
|---|---|
| Input Voltages: | (-SP2 Option) 125 VDC input using the DCS-1 Power  Supply.  | 
All specifications are subject to change without notice.
