![background image](http://html1.mh-extra.com/html/carrier/50lc-14/50lc-14_service-and-maintenance-instructions_2561601034.webp)
34
Fig. 44 — Optional or Accessory Electric Heater
Control Connections
RTU Open Control System
For details on operating units equipped with the factory-in-
stalled RTU Open controller, refer to the
“Factory-Installed
RTU Open Multi-Protocol Controller Control, Start-Up, Oper-
ation and Troubleshooting”
manual.
SYSTEMVU™ (FACTORY OPTION)
For details on operating 50LC*14-26 units equipped with the
factory installed SystemVu control option, refer to the
48/50LC
14-26 Single Package Rooftop Units with SystemVu Controls
Version 1.X Controls, Start-Up, Operation and Troubleshoot-
ing
manual.
Integrated Staging Control (ISC) Board
ISC BOARD - SEQUENCE OF OPERATION
General
The Carrier Integrated Staging Control (ISC) is intended for
use with a standard thermostat or direct digital control (DDC)
capable of three cooling stages. After initial power to the
board, a Green LED will blink with a one second duty cycle in-
dicating the unit is running properly. In the event of the ISC
board failing, the Green LED will be OFF or continuously ON.
When the unit is not running properly, the Green LED will
blink along with Red LED lights. The Red LED light configu-
ration will indicate the type of error the board has identified.
See Fig. 45 for LED locations and Table 5 for a list of status
codes.
The ISC board can be remotely shutdown by removing
Jumper 4 and wiring to the Remote Shutdown terminal. The
Smoke Control Module can shutdown the unit by removing
Jumper 3 and wiring to the Smoke Shutdown terminal. The
Smoke Alarm terminal on the ISC Board provides a pass
through connection should a smoke alarm signal be connected.
In the case of the RTU Open option, the RTU Open controller
provides the signal which is passed through the ISC board to
the Smoke Alarm terminal.
The crankcase heater will run at all times except when the
compressors are running. An auxiliary power supply (24vac)
available at TB-4 Terminal is provided to power auxiliary
equipment. An optional Phase Monitor Relay can be wired to
the PMR terminal by removing Jumper 5. An optional Conden-
sate Flow Switch can be wired to the COFS Terminal by re-
moving Jumper 7.
Ventilation
In the Ventilation/Fan Mode (G on the thermostat), the indoor-
fan will run at low speed and the damper will operate at mini-
mum position.
NOTES:
1. Green LED Blinking at 1HZ indicates normal operation.
2. Solid red LED indicates an error exists, see a
b
ove LED configuration.
INTEGRATED
STAGING
CONTROL
(ICS)
BOARD
Table 5 — Status Code Descriptions for ISC Board LEDs
ERROR# ERROR
NAME
LED INDICATION
LED01 LED02 LED03 LED04 LED05
1
Check Smoke Detector/PMR/AUX
RED
Blinking
Green LED
(Note 1)
2
Check HPS/LPS/COFS
RED
RED
3
Call for Y3 with no call for Y1. Check Y1 wiring.
RED
4
Call for Y3 with no call for Y1/Y2. Check Y1 wiring.
RED
RED
5
Call for Y2 with no call for Y1. Check Y1 wiring.
RED
RED
6
Call for W2 with no call for W1. Check W1 wiring.
RED
RED
7
Call for heat (W1/W2) and cooling (Y1/Y2/Y3). Check
thermostat wiring.
RED
RED
RED
RED
8
Call for heat (W1/W2) with no G. Check G wiring.
RED
RED
RED
9
Call for cooling (Y1/Y2/Y3) with no G. Check G wiring
RED
RED
RED
10
Call for heat (W1/W2) and cooling (Y1/Y2/Y3) with no G.
Check thermostat and G wiring.
RED
RED
RED
11
Check ISC Board and the thermostat wiring
RED
RED
RED
12
Check ISC Board and the thermostat wiring
RED
13
Check ISC Board and the thermostat wiring
RED
RED
14
Check ISC Board and the thermostat wiring
RED
15
Check ISC Board and the thermostat wiring
RED
RED
Summary of Contents for 50LC 14
Page 26: ...26 Fig 34 50LC 14 26 Control Wiring Diagram...
Page 27: ...27 Fig 35 50LC 14 26 RTU Open Control Wiring Diagram...
Page 28: ...28 Fig 36 50LC 14 20 208 230V 3 Phase Power Wiring Diagram...
Page 29: ...29 Fig 37 50LC 24 26 208 230V 3 Phase Power Wiring Diagram...
Page 30: ...30 Fig 38 50LC 14 26 460V 575V 3 Phase Power Wiring Diagram...