Product Specification Sheet APS674

Rev. 07/2013

PK250B Power/Standy Power Supply U.P.S.

PK250B Power/Standby UPS

The Alpha Communications® / TekTone model PK250B Uninterruptable Power Supply is primarily used with the NC300 / NC300II series and/or HC345C series microprocessor based nurse/emergency call systems and provides for uninterrupted power in the event of utility power failures, voltage surges, spikes, brownouts and blackouts. It's economical cost and extremely compact size will enhance the operation of all your NC300, NC300II and HC345C systems.

When power is interrupted, the PK250B immediately cuts in to provide square wave power for the system's central processing equipment until an emergency generator is activated or power is restored. In the event of a prolonged power outage, the PK250B will provide power to the limit of its battery.

The green LED on the front panel indicates power line output when steady and battery output when flashing. The unit also provides an audible tone during battery output operation.

Other features include output receptacles for connection of equipment, power cord for standard 120 volt, 15 amp power circuit, AC fuses to protect the unit from utility power and DC fuses to protect the battery.

The PK250B is U.L. 1778 and CSA 22.1 Listed.

Architects' And Engineers' Specifications

The (300VA) Uninterruptable Power Supply shall be Alpha Communications® / TekTone PK250B or approved equivalent, and shall provide for continuous power in the event of voltage surges, spikes, brownouts, blackouts, or similar power interruptions. The power supply has rugged construction and shall include power switch, audible alarm indicator, line output indicator, battery output indicator, output receptacle, power cord and AC/DC fuses for utility power and battery protection. The PK250B is used primarily with the NC300, NC300II and/or HC345C series microprocessor nurse-call and emergency-call systems, but can be used with other nurse-call, emergency-call and annunciator or intercom systems as well.

The PK250B shall be U.L. 1778 and CSA 22.1 Listed.

  • Wattage: 300W
  • Voltage: 115 VAC
  • Frequency: 60Hz
  • Waveform: Stepped square wave
  • Voltage: 115 VAC
  • Frequency: 60 Hz
  • Ampere (max): 2.6
  • At full load: 2 minutes
  • At half load: 9 minutes
  • Transfer time: 6 ms typical
  • Type: Maintenance-free 12VDC 5Ah
  • Recharge: 8 hours
  • Auto cut-off: Yes
  • Overall: 3.50"W x 10.90"H x 10.80"D
  • Weight: 13.5 lbs.

Operating temp range is 0C40C.
Installation and Initial Operation
  1. Remove unit from shipping carton and examine for damage or moisture. Do not try to operate the unit if it appears damaged.
  2. Read the following installation and operation instructions completely.
  3. Locate the unit in a dry, well ventilated area. This unit is designed for indoor use only. Never use outdoors.
  4. Be sure power switch is in the OFF position.
  5. Plug the DC fuse into the DC fuse receptacle at the rear of the unit.
  6. Plug the power line cord into any standard 120 volts, 15 amp AC outlet. Turn the unit ON and allow at least 30 minutes to change the batteries to their full potential. Turn the unit OFF. Once, installed, leave the unit plugged in at all times.
  7. Plug the NC350C series CPE (Central Processing Equipment) into their output receptacle located at the rear of the unit. Make sure the CPE is turned OFF. NOTE: Only (1) CPE may be used per PK250B.
  8. Turn the alarm switch to ON.
  9. The PK250B is now ready for operation in the event of utility power problems
Test for correct operation of the PK250B as follows:
  1. Be sure NC350C series CPE is not in use.
  2. Disconnect power line cord from the wall socket. The green output indicator light will start to flash. The alarm will start to beep, indicating a loss of incoming utility power. The NC350C series CPE (and any additional equipment) should continue to function normally on internal battery power provided by the PK250B's backup system.
  3. Reconnect the power line. The red output battery indicator will go off. The green output power indicator light will come on, steadily signaling the return of utility power. The alarm will go off.
  4. The PK250B is completely automatic and will operate on its own once installed. Controls will need to be reset only after extended power outages or battery drain occurs.
If the PK250B fails to operate as described, check for the following:
  1. Determine if power line cord is firmly plugged into a live wall outlet.
  2. Check that power switch is in the ON position.
  3. Check the fuses on back panel. Unscrew the black caps and remove the fuses. Check visually for proper condition. Replace in the proper slots after checking.
Extended Power Outage
A built-in control feature protects the battery from damage due to deep discharge beyond its normal capacity. During a prolonged power outage, the PK250B will provide power to the limit of its battery. Beyond this point, the unit will shut down the battery circuitry. If this happens, the power switch must be turned OFF. Wait until utility power is restored and turn power switch ON. Allow 15 hours to recharge before the unit is ready to provide power again.
When the PK250B is not in use, leave it plugged into the power supply and turn power switch OFF. This will prevent damage to battery from discharge.
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