Nomenclature 25 ton to 80 ton model number
Digits 1–2: Product brand name
GT: Tempmaster
Digit 3: Capacity
A: 25 ton
B: 30 ton
C: 40 ton
D: 50 ton
F: 60 ton
H: 70 ton
J: 80 ton
Digit 4: Efficiency
1: Standard capacity, standard efficiency, staged control
2: Standard capacity, high efficiency, modulating control
3: High capacity, standard efficiency, staged control*
4: Standard capacity, standard efficiency, low sound, staged
control*
5: Standard capacity, high efficiency, low sound, modulating
control*
6: High capacity, standard efficiency, low sound, staged
control*
Digit 5: Heat source
A: Cooling only
B: Staged gas aluminized burner
C: Staged gas stainless steel (SST)
G: Modulating gas stainless steel
K: Steam coil*
L: Hot water coil*
M: Electric heat*
Digit 6A: Electric heat capacity
0: None
1: Low heat*
3: High heat*
4: Low heat with silicon controlled rectifier (SCR)*
6: High heat with SCR*
Digit 6B: Natural gas heat capacity
0: None
1: 250 MBH
2: 500 MBH
3: 750 MBH
4: 1,000 MBH
5: 1,250 MBH
6: 1,500 MBH
Digit 6C: Hot water or steam heating coil option
0: None
1: Low heat without valves*
2: Low heat with valves*
3: High heat without valves*
4: High heat with valves*
Digit 7: Unit type
A: Single zone VAV (SZVAV) (no duct pressure transducer)
B: Variable air volume (VAV) (duct pressure transducer)
Digit 8: Motor control options
1: Supply fan variable frequency drive (VFD)
2: Supply fan VFD with line reactor*
3: Supply fan VFD with bypass (redundant VFD) / Supply fan
with dual VFD
4: Supply fan VFD with line reactor and bypass (redundant
VFD) / Supply fan with dual VFD with line reactor*
5: Supply fan VFD and return/exhaust fan VFD
6: Supply fan VFD with line reactor and return/exhaust fan
VFD with line reactor*
7: Supply fan VFD and return/exhaust fan VFD with bypass
(redundant VFD for supply fan and bypass for return or
exhaust fan) / Supply fan with dual VFD and redundant VFD
for return fan / manual bypass for exhaust fan
8: Supply fan VFD with line reactor and return/exhaust
fan VFD with line reactor with bypass (redundant VFD for
supply fan and bypass for return or exhaust fan / Supply
fan with dual VFD and redundant VFD for return fan /
manual bypass for exhaust fan, and line reactors (for all
fans)*
Digit 9: Voltage
A: 208-230 V 3Ph 60 Hz, single point terminal block
B: 208-230 V 3Ph 60 Hz, dual point terminal block
C: 208-230 V 3Ph 60 Hz, single point non-fused DISC
D: 208-230 V 3Ph 60 Hz, single point terminal block, 65KA
short-circuit current rating (SCCR)*
E: 208-230 V 3Ph 60 Hz, dual point terminal block, 65KA
SCCR*
F: 208-230 V 3Ph 60 Hz, single point fused DISC, 65KA SCCR*
G: 460 V 3Ph 60 Hz, single point terminal block
H: 460 V 3Ph 60 Hz, dual point terminal block
J: 460 V 3Ph 60 Hz, single point non-fused DISC
K: 460 V 3Ph 60 Hz, single point terminal block, 65KA SCCR*
L: 460 V 3Ph 60 Hz, dual point terminal block, 65KA SCCR*
M: 460 V 3Ph 60 Hz, single point fused DISC, 65KA SCCR*
N: 575 V 3Ph 60 Hz, single point terminal block
P: 575 V 3Ph 60 Hz, dual point terminal block
Q: 575 V 3Ph 60 Hz, single point non-fused DISC
R: 575 V 3Ph 60 Hz, single point terminal block, 65KA SCCR*
S: 575 V 3Ph 60 Hz, dual point terminal block, 65KA SCCR*
T: 575 V 3Ph 60 Hz, single point fused DISC, 65KA SCCR*
Digit 10: Return configuration
A: Bottom return, right outside air (OA), side exhaust
B: Bottom return, right OA, front exhaust
C: Bottom return, left OA, side exhaust
D: Bottom return, Left OA, front exhaust
E: Top return, right OA, side exhaust (no return fan
available)*
F: Top return, right OA, front exhaust (no return fan
available)*
G: Top return, left OA, side exhaust (no return fan
available)*
H: Top return, left OA, front exhaust (no return fan
available)*
J: Left return, right OA, front exhaust
K: Right return, left OA, front exhaust*
L: Front return, left OA, right exhaust*
M: Front return, right OA, feft exhaust*
N: Bottom return, no OA, no exhaust air (EA) (no return fan
available)
P: Top return, no OA, no EA (no return fan available)*
Q: Left return, no OA, no EA (no return fan available)
R: Right return, no OA, no EA (no return fan available)*
S: Front return, no OA, no EA (no return fan available)*
Digit 11: Discharge locations
1: Bottom discharge, from discharge plenum
2: Bottom discharge, discharge through heat section
3: Top discharge, from discharge plenum*
4: Right discharge, from discharge plenum
5: Left discharge, from discharge plenum
6: Left discharge, discharge through heat section
Digit 12: Supply configuration
A: None
B: Small blank
C, D: Large blank*
E, G: Large blank with final filter*
F: Small blank with humidifier and SST drain pan*
H, K: Large blank with humidifier and SST drain pan*
L: Small blank sound attenuator*
M, N: Large blank sound attenuator*
P: Small blank final filter
Q, T: Large blank with sound attenuator and final filter*
S, V: Large blank with sound attenuator and humidifier and
SST drain pan*
Digit 13: Final filter options
1: MERV 15 bag final filters with 2 in. MERV 8 filters
2: MERV 14 rigid final filters with 2 in. MERV 8 filters
3: MERV 17 high efficiency particulate air (HEPA) final filters
with 2 in. MERV 8 filters*
4: MERV 14/15 filter rack (no filters)
5: HEPA filter rack (no filters)*
6: None
Digit 14: Final filter control options
0: None
1: Combined pre- and post- filter transducer
2: Separate pre- and post- filter transducer
3: Combined pre- and post- filter transducer and combined
magnehelic gauge
Tempmaster
®
Omni™ Premier 25 Ton to 80 Ton Rooftop Units Installation and Maintenance Guide
6
Tempmaster
