RTR-2A/B
Pulse Isolation Relay for Badger 'RTR' and Hersey 'ER' Water Meters

GENERAL DESCRIPTION

Click photo for larger view The RTR-2A pulse isolation relay is designed for use with Badger's Record-All Transmitter Register (RTR) water meters and Hersey's ER-2 water meters. The RTR-2B pulse isolation relay is designed for use with Hersey's ER-1 water meters. Both RTR-2x relays provide two sets of isolated "dry", mercury-wetted "Form A" (K & Y) contacts. The RTR-2's input is designed for an open-collector transistor, open drain FET or a dry-contact relay. The input is activated when the input is grounded (pulled to ground) for 5 milliseconds or longer for the RTR-2A and 50 microseconds or longer for the RTR-2B.

If Badger's RTR water meter provides an open collector transistor output to interface to Badger's remote meter reading equipment, the RTR-2 relay is inserted in the two conductor cable between the RTR meter and the remote equipment. The RTR-2 provides a replicated signal to the remote equipment, and a separate isolated Form A contact closure for use with customer-owned monitoring equipment.

Typical applications involve pulse counting, monitoring and recording of water usage. Other applications include interfaces between utility metering devices and customer-owned building automation systems, control and monitoring systems, usage recorders, automated meter reading systems and supervisory control systems (SCADA). A bright yellow LED lamp indicates the system's status at all times thus allowing a rapid check of the system's performance without requiring any additional test equipment.

The RTR-2 has an integrated circuit that checks each incoming pulse for its duration. If the incoming pulse is less than 5 milliseconds in length the RTR-2A assumes the incoming pulse to be noise and it is disregarded. (Less than 50 microseconds for the RTR-2B.) Thus any valid pulse rate of 100 pulses per second (50 on-50 off form factor) or less is accepted while static and induced high frequency noise is rejected. If used in a very noisy environment this "pulse acceptance window" may be lengthened or shortened as needed to reject noise by the change of a resistor and/or a capacitor value. The RTR-2's Form A output pulse dry contact closure is set for a nominal 100 millisecond closure, regardless of the input pulse's duration. The 100 millisecond factory set duration may be changed by changing either a resistor and/or a capacitor for longer or shorter durations. The RTR-2's dry contact closure allows a pulse of approximately 100mS to the remote equipment & allows the revenue water meter display to operate normally.

The RTR-2's input and output circuit's terminal strip is a "Euro" type terminal strip for easy field wiring. The "K" lead of the RTR-2's output is fused to prevent damage to the relay under almost any conditions a user might cause such as excessive current, incorrect wiring, etc. The RTR-2 has built-in transient protection for the mercury-wetted relay's contacts which eliminates the need for external or off-the-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 user protection. The mounting base plate is made of polycarbonate and offers excellent electrical insulation between the circuit and the mounting surface.

RTR-2A/B SPECIFICATIONS

ELECTRICAL

Power Input 90 to 325 VAC. Burden: 10 MA. at 120 VAC
Output Two - Two sets of "dry" Form A (K & Y) contacts. Outputs are activated (closed) for a nominal 100mS following a valid input pulse. The contacts are mercury-wetted "no bounce" relays rated at 500 VDC or 350 VAC 2 Amps. break, 5 amps carry. The maximum rating of the contacts is 100 VA. Factory fused at 1/2 amp. (3AG)
Contact Resistance 50 milliohms maximum, 12 to 14 typical
Insulation Resistance 50 megohms typical
Operate and Release Time 1 to 2 milliseconds typical

MECHANICAL

Mounting Within 30 degrees of vertical
Size 3.27 inches wide, 5.65 inches high, 1.50 inches deep
Weight 13 ounces

TEMPERATURE

Temperature Range -38° C to +70° C, -36.4° F to +158° F
Humidity 0 to 98% non-condensing

OPTIONS

Input Voltages 125 VDC input using the DCS-1 Power Supply. Contact factory for other input voltages.