RTC AP21 Series Operation & Service Manual

AP21 Series T ime Switch

Operation/Service Manual

(use this manual for Ver 3.02 and higher)

“Helping Kids Get To School Since 1987”

RTC Manufacturing, Inc.

1016 Enterprise Place * Arlington, TX 76001

www.rtc-traffic.com

[phone]

AP21 SERIES TIME SWITCH

OPERA TION/SERVICE MANUAL
Table of Contents 2
A. Introduction 3
B. Specifications

Programming Capabilities 3
Electrical 3
Power Fail Backup 4
Accuracy 4

Physical 4
C. Wiring 4
D. Description of Display and Keyboard

Alpha-Numeric Display 5

Keyboard 5

E. Programming Instructions

AP21 Cursor 6

Auto Prompt Display 6

Entering Data 6

Quick Reference Program Guide 7

Program Guide Key 8

Special Code 8

Time Switch Keys 8

Programming Procedures for:

TIME 8

DATE 9

DAY 9

DST 9

BASIC Program Steps 10

ANNUAL Program Steps 10

SLEEP MODE 11

PULSE 11

MANUAL Operation 12

SECONDS Display 12

PROGRAM TRANSFER 12
F. Warranty 12

G. Service 12
H. Theory of Operation 13

I. Schematic & Part List 13

2

AP21 SERIES OPERATOR’S MANUAL

OPERATIONS/SERVICE MANUAL

A. INTRODUCTION

The AP21 is an single circuit, calendar programmable solid state time switch. It is used for switching electric circuits
according to pre-set time and date program. The AP21 AUT O PROMPTING alpha-numeric display makes programming fast
and simple. It is designed to control zone flashers, time-of-day flash, or any other traffic application where holiday skip is
desired. The output relay is rated at 120 VAC, 15 amps resistive load. The output can be programmed for momentary
operation such as required for ringing bells in school, churches or industrial facilities. The relay output can also be disabled by
SLEEP MODE function to allow time switch to maintain data without operating the relay.

B. SPECIFICATION

PROGRAMMING CAP ABILITIES

1. Auto Prompting Display - Provides display information to guide the operator during programming. From a cold start it will
prompt the operator in setting the time through setting the basic program steps.

2. 16 Program S teps - Each step can be programmed for a specific day of the week, for Monday through Friday only , for
Saturday and Sunday only , or for every day of the week.

3. 10 Skip Plans - Each skip plan has a starting and ending date that prevents the output relay from activating. This
feature can be used to skip a specific day or a group of consecutive days.

4. Programmable Daylight Saving T ime Adjustment - The AP21 can be programmed to automatically adjust its time for
daylight savings time changes according to U.S. law, even if the law changes.

5. Automatic Leap Year Compensation.

6. Manual Override - The output relay can be manually energized or de-energized from the keyboard. The manual
override remains in effect until the next programmed step occurs.

7. Sleep Mode - Deactivates relay output while maintaining all timing data during summer vacation.

8. Pulse Output - The output can be programmed to operate as constant contact or a momentary contact programmable
from 1 to 99 seconds.

9. Program Transfer - This option allows the operator to program an AP21 and download that program to another AP21 with
the use of a simple unit-to-unit transfer cable.

ELECTRICAL

Power Requirements - 95V AC to 135VAC, 60HZ., 3 V A maximum.

10.5VDC to 14.3VDC less than 1 Watt through full

range of supply volt age (0.2 to 0.58 average)
Outputs - AP21, SPDT relay rated at 15 AMP resistive at 120VAC.
Wiring - T erminal block can accommodate #10 to #24 AWG wire.

3

POWER FAIL BACKUP

Program and time keeping is maintained for 48 hours on a rechargeable capacitive backup system in the event of a power
failure. The output and display are disabled during backup. The AP21 resumes normal operation when power is restored.

ACCURACY

Time Keeping - Synchronous with the AC power line and 4 PPM on DC power. During a power failure it is quartz crystal
controlled with an accuracy of +/-.005% throughout its full temperature range.

Programmed Events - On/Off events are programmable with a one minute resolution and occur at the zero second of that
minute.

PHYSICAL

3.7"W x 8.0"H x 1.55"D
Weight - Approximately 2 lbs.
Mounting - Mounting hole provided (AP21/AP21T).
Operating Temperature Range - -30 to +74 C.

C. WIRING

Remove power before wiring connection. Observe all safety precautions.

AP21

AC-

AC+ COM

GND

N/O-12V+12V

N/C

Terminal Block

Relay moveable (in)
Relay N/O (out)

TXDOT Wiring AP2T/CPR

Standard Wiring AP21T/CPR

AP21TR OCT AL BASE MOUNT PIN OUT (Discontinued product)
T o install the AP21TR requires an eight pin oct al base Potter and Brumfield #27E122 or equal. Mount this base in a suitable
location and wire the terminals of the base as follows:

AC Version DC Version

1. Relay Common 1. Relay Common

2. Line 2.

3. Relay normally open 3. Relay normally open

4. Relay normally closed 4. Relay normally Closed

5. 5.

6. 6. -12VDC

7. Neutral 7.

8. 8. +12VDC

4