Watlow PM LEGACY™ Limit Controller  •  112  •  Appendix
Specifications
Line Voltage/Power
• 85 to 264VAC, 47 to 63Hz
• 20 to 28VAC, +10/-15%; 50/60Hz, ±5%
• 12 to 40VDC
• 10VA (1/32 and 1/16 DIN)
• Data retention upon power failure via non-volatile 
memory
• Compliant with SEMI F47-0200, Figure R1-1 voltage 
sag
requirements @ 24VAC or higher
Environment
• 0 to 149°F (-18 to 65°C) operating temperature
• -40 to 185°F (-40 to 85°C) storage temperature
• 0 to 90% RH, non-condensing
Accuracy
• Calibration accuracy and sensor conformity: ±0.1% of 
span, ±1°C @ the calibrated ambient temperature and 
rated line voltage
• Type S: 0.2%
• Type T below -50°C: 0.2%
• Calibration ambient temperature @ 77°F ±5°F (25°C 
±3°C)
• Accuracy span: 1000°F (540°C) min.
• Temperature stability: ±0.1°F/°F (±0.1°C/°C) rise in 
ambient max.
Agency Approvals
• cULus® UL/EN/CSA C22.2 No 61010-1 Listed, File 
E185611
• CSA C22 No. 24, File 158031, class 4813-02, CSA 
approved
• UL® Type 4X indoor use front panel seal
• NEMA 4X, IP66, IP67 front panel seal
• cULus® ANSI/ISA 12.12.01-2007, CSA-C22.2 No. 
213-1987,
Class 1, Div. 2, Groups A, B, C and D, temperature code 
T4A, File E184390 (optional)
• CE, RoHS by design, W.E.E.E.
• FM Class 3545 (limit controls) 
Controller
• User selectable heat/cool, on-off, P, PI, PD, PID or 
alarm action, not valid for limit controllers
• Auto-tune with control algorithm
• Control sampling rates: input = 10Hz, outputs = 10Hz
• Input and output capacity per controller type ordering 
information
Serial Communications 
• Isolated communications
• Standard bus configuration protocol
Wiring Termination—Touch-Safe Terminals
• Input, power and controller output terminals are touch 
safe removable  
12 to 22 AWG
Universal Input
• Thermocouple, grounded or ungrounded sensors, 
greater than 20MΩ input impedance, 2kΩ source 
resistance max.
• Non-isolated to switched dc and process output
• RTD 2- or 3-wire, platinum, 100Ω @ 0°C calibration 
to DIN curve (0.00385 Ω/Ω/°C)
• Process, 4-20mA @ 100Ω, or 0-10VDC @ 20kΩ 
input impedance; scalable
Functional Operating Range
Type J: -346 to 2192°F (-210 to 1200°C)
Type K: -454 to 2500°F (-270 to 1371°C)
Type T: -454 to 750°F (-270 to 400°C)
Type E: -454 to 1832°F (-270 to 1000°C)
Type N: -454 to 2372°F (-270 to 1300°C)
Type C: 32 to 4200°F (0 to 2315°C)
Type D: 32 to 4200°F (0 to 2315°C)
Type F: 32 to 2449°F (0 to 1343°C)
Type R: -58 to 3214°F (-50 to 1767°C)
Type S: -58 to 3214°F (-50 to 1767°C)
Type B: 32 to 3300°F (0 to 1816°C)
RTD (DIN): -328 to 1472°F (-200 to 800°C)
Process: -1999 to 9999 units
Output Hardware
• Switched dc = 22 to 32VDC @ 30mA
• Open collector = 30VDC max. @ 100mA max. cur-
rent sink
• Solid state relay (SSR), Form A, 0.5A @ 24VAC 
min., 264VAC max., opto-isolated, without contact 
suppression
• Electromechanical relay, Form C, 24 to 240VAC or 
30VDC max., 5A resistive load, 100,000 cycles at 
rated load
• Electromechanical relay, Form A, 24 to 240VAC or 
30VDC max., 5A resistive load, 100,000 cycles at 
rated load
• Output 2 is limit for limit models
• NO-ARC relay, Form A, 24 to 240VAC, 15A @ 122°F 
(50°C), resistive load, no VDC, 2 million cycles at 
rated load
• Universal process output: range selectable; 0 to 
10VDC ±15mV into a min. 1,000Ω load with 2.5mV 
nominal  resolution; 4 to 20mA ±30μA into max. 800Ω 
load with 5μA
nominal resolution; temperature stability 100ppm/°C 
Operator Interface
• Dual 4 digit, 7 segment LED displays
• Typical display update rate 1Hz
• Advance, infinity (RESET), up and down keys plus 
an A/M-KEY for control or  
FUNCTION for limit (not available in 1/32 DIN)
• Infinity key is also labeled RESET on limit control 
models
• A/M-KEY on 1/16 DIN package automatically pro-
grammed as an auto/manual transfer mode function 
on PID models.