Figure 1. gpt–3 dimensional drawing – King Electric GPT 3 User Manual
Page 8
Page 8 of 21
the control sensor temperature, the GPT–3 may momentarily declare a cold heater.
The GPT–3 automatically executes a self-test every 24 hours. First, heaters are de-
energized. Then, the GFEP verifies its own operation. Finally, it checks the heaters for ground
fault under operating conditions. This entire process takes about two seconds.
Other features include verifying the integrity of both the control and monitor temperature
sensors and checking the contactor for open or shorted contacts. A control temperature sensor
failure also inhibits contactor operation in addition to asserting an alarm condition.
The GPT–3 automatically accommodates 120, 208, 240 and 277 supply voltages. Since
the heaters and the GPT–3 operate from the same supply voltage, the safety hazard created by
multiple points of disconnect is eliminated. The heater control contactor is rated for up to 30
amps.
The GPT–3 provides a reverse acting isolated Class 2 alarm relay contact SPDT rated at one
amp. Reverse action makes absence of supply voltage an alarmed condition.
Although the GPT–3 housing is NEMA 3R rated for indoor or outdoor service, a protected
location is recommended. The operating temperature range is −40° to 136° F (−40° to 58°C).
Padlocking the transparent front cover can prevent tampering without interfering with the view
of the status indicators.
GPT
®
–3
TRACON
®
GFEP
FAULT
SUPPLY
HEATER
GFEP
RESET
TEST
HEATER
FAULT
Temperature
20
15
68
59
25
77
10
5
50
41
°C
°F
We Manage Heat
®
http://www.networketi.com
e-mail: [email protected]
®
J1
3
/
4
" (21mm)
Conduit Entry
11
1
/
2
"
(292mm)
12"
(305mm)
4"
(102mm)
2
1
/
8
"
(54mm)
2"
(51mm)
2
5
/
16
"
(59mm)
9
1
/
8
"
(232mm)
5
1
/
2
"
(140mm)
6
9
/
16
"
(167mm)
3
/
4
" (21mm)
Conduit Entry
L
C
L
C
L
C
Low Voltage
Compartment
High Voltage
Compartment
Grounding Lug
Figure 1. GPT–3 dimensional drawing